There are "budget" tops, like Pavement Ends (Bestop's budget brand). But even those are going to stretch your budget.
Look at it this way: It's hard to buy a coat for less than $100 anymore. And a soft top has all sorts of metal hardware, Velcro, vinyl windows, zippers, and yards of fabric. These are complicated objects.
If you find a used one, PLEASE post something here before you buy it, and ask the experts at this site if the top sounds like a good deal, and if it has all the hardware you need. I don't want you to buy something, and then discover it doesn't work.
And congrats on youur new Jeep.