If you're an American who doesn't want to import it.

Across Europe, copies of Jazz 2 are a dime a dozen(Not literally, but they're everywhere, and they're very cheap).

Jazz 1 is... Yeah, a lot more difficult. Still, keep an eye out, and you should be able to get a copy eventually. I got a sealed copy on eBay for like £13 a few years ago.

As Violet said, Epic owns Jazz. Since Epic apparently doesn't like money, or games with colours in them these days, you're unlikely to see it pop up on Steam any time soon.

Still, they'll probably release all their older games someday. There's enough demand for them on sites like GoG.