I'm the procurement manager at a 120-person education supply company, and I've managed our equipment budget (about $180,000 annually) for 6 years. In that time, I've bought graphing calculators, printer cartridges, a Bambu 3D printer, and once had to explain how a dry erase marker got onto our office couch. So when people ask me what to buy, the honest answer is: it depends.

This article is a decision tree, not a product ranking. I'll walk you through four common scenarios and tell you what I'd do in each. Then I'll help you figure out which scenario you're in.

Scenario A: You need graphing calculators for a classroom or team

The two Casio models I get asked about most are the casio fx-9860giii graphing calculator and the casio calculator fx-9750gii. People expect a clear winner. There isn't one.

The fx-9750GII is a solid graphing calculator. It handles algebra, trigonometry, statistics, and what most high school students need. The fx-9860GIII adds more memory and Python support. If your curriculum or exam board requires Python programming, choose the 9860GIII. If not, the 9750GII is often enough, and the price difference can be used for spare units. According to Casio's official product listing, the fx-9860GIII supports Python and has more flash memory than the fx-9750GII. Based on the online retail listings I checked in March 2025, the 9750GII also tends to cost less, though prices shift.

When I compared the two side by side for our STEM program, I finally understood why the extra memory mattered. The 9860GIII lets students save programs and take them between classes more easily. But for a standard algebra course, those extra features sit unused. (Should mention: we also tested USB file transfer, which is genuinely helpful for updating calculators in bulk. The 9750GII has I/O too, but the 9860GIII's file management is smoother.)

I recommend the fx-9750GII if your needs are basic. But if you're dealing with a curriculum that includes coding, you might want to consider the fx-9860GIII instead. This worked for us because our district already standardized on Casio. If you're starting from zero, focus on teacher familiarity first. The best calculator is the one instructors understand.

Scenario B: You're choosing an Epson printer

When our office needed a new department printer in Q2 2024, I compared an Epson cartridge model and an Epson EcoTank model. I assumed the cartridge model would be cheaper because the initial price was lower. Didn't verify page yields. Turned out the cartridge model would have cost us about $2,300 more over two years, based on our volume of roughly 2,000 pages per month. Epson's own page yield estimates, which I checked on their spec sheet, confirmed the gap.

That's the classic total cost of ownership mistake. The upfront price is only one line item. You have to include ink, paper waste, and the labor of changing cartridges.

If your office prints less than 300 pages per month, a cartridge Epson printer is fine. If you're over 800 pages per month, a tank system makes more sense. If you're in between, track your actual page count for 90 days before buying. (I built our current cost tracking sheet after getting burned on a 'cheap' printer that ate cartridges every three weeks.)

The Epson printer decision isn't about brand loyalty. It's about page volume, print quality, and whether you have someone who can refill tanks without making a mess. At least, that's been my experience with office documents. If you print mostly thick media or specialty materials, the calculus might be different.

Scenario C: Should you buy a Bambu 3D printer?

We bought a Bambu 3D printer after relying on an external service for prototype parts. For a year, each small prototype cost about $80 plus shipping and a 4-day wait. After we hit eight revisions on a mounting bracket, the expense became ridiculous. The printer paid for itself faster than I expected because the material cost per part was under $10.

But don't buy a Bambu 3D printer just because it's cool. That's how budgets die. If you need one prototype per quarter, a print service will be cheaper and you won't have to maintain a machine. If you're iterating weekly, an in-house printer changes the speed of your projects, not just the cost.

I can only speak to small to medium plastic parts. If you're doing production-grade functional parts, you need a very different setup. Our Bambu printer is a tool for concept validation, not a replacement for an engineering workshop.

Also factor in the hidden costs: time to learn the slicing software, failed prints, spare parts, and where to put it so the office couch doesn't become a filament storage area. (Yes, I'm aware of the irony of bringing the couch back up.)

Scenario D: How to get dry erase marker out of couch

This is not a procurement question, but someone on our team famously drew a workflow diagram on the conference room couch during a whiteboard shortage. So here's the answer I would give my past self.

First, blot the marker stain with a dry white cloth to remove as much pigment as you can. Don't rub. Rubbing pushes the marker deeper into the fibers.

Then, test rubbing alcohol on an inconspicuous spot, like under a cushion. If the fabric is safe, dab the stain with an alcohol-dampened cloth. Work from the outside edge toward the center. The dry erase marker should start transferring to the cloth. Keep changing the cloth as it picks up color.

Once the stain is gone, rinse the area with a little mild soap and water, and blot until dry. If the stain has set, hand sanitizer can work because it contains alcohol. Avoid a dryer until you're sure the stain is gone. Heat can make it permanent.

The easiest method is to act fast. I should add that a dry erase marker is usually easier to remove than a permanent marker because it contains solvent and pigment that can be dissolved. But a fabric couch is still unforgiving, so test first.

How to know which scenario you're in

Ask these three questions before you send a purchase order:

  1. Do your students or staff need to write and run Python programs on the calculator? If yes, the casio fx-9860giii graphing calculator is worth the premium. If no, the casio calculator fx-9750gii probably does the job.
  2. What is your actual monthly print volume? Look at your last 90 days of usage data. High volume means an Epson EcoTank or similar tank printer. Low volume means a cartridge Epson printer is fine.
  3. How many prototype parts do you expect in the next 12 months? More than six? A Bambu 3D printer might be justified. Fewer? Use a service and save the floor space.

And if someone drew on the couch, start with blotting and rubbing alcohol. After that, it's just a furniture stain, not a budget crisis. (Well, unless the replacement couch shows up in Q3.)

The honest bottom line

There is no universal best Casio calculator, Epson printer, or Bambu 3D printer. There is only the best fit for your specific budget, volume, and skill level. I know that sounds like a consulting wrap-up, but it's also what I've learned from six years of invoices.

If you want a straightforward rule: choose the fx-9750GII for basic graphing, choose the fx-9860GIII for Python and larger programs, choose an Epson tank printer for high volume, and choose a Bambu 3D printer only if you'll use it weekly. For the couch, choose rubbing alcohol and a patient hand.