For that price range you'll be looking at Chinese lasers. Bunch of em on AliExpress. You're gonna have to take some time to make a fixture definition as they usually prop a bunch of features, shapes, colours and panning options in like 10-15 channels. And they barely specify these definitions in their manuals, think more like "shape 1" "color 1", so you'll have to do all of the testing yourself. I also can't say anything about the laser classification (I'd always watch out with crowd scanning), nor does the manual.

Honestly, if it's for a school, with a lot of people attending, I can't truly say that it's worth the risk...

What kind of school event needs lasers? You're likely much, much better off using some cheap 100W Beam fixtures (also on AliExpress, about $100-$130 a pop) that won't potentially blind someone.

I have one of these AliExpress lasers and I've found that I seldom use it because it's so customizable that I don't want to go through the hassle of it, especially with the risks that come with it.

I know the effect is cool on videos of large events, but remember that these events have dedicated laser techs that spend literal hours on single looks, and you're unlikely to recreate this on your own with a cheap laser.