>I would love to get my students using slide rules, but it's difficult to find physical ones for a reasonable price.

What's your idea of a reasonable price? I know it's going to be a bulk pack.

This sounds like a hobby project challenge. The scales are easy to do with CNC and computers, or laser printers. You need a small bit of routing, or a rabbit plane, to make the groves to hold the slide in. The two ends. The hairline/scale is the trickiest bit because you want a leaf spring making it slide nice, but hold its position.

It might be something the folks at your friendly makerspace find an interesting challenge. I know I would, were I not having eye surgery and a month or two of "don't do anything fun" ahead of me tomorrow.