My suggestion would to be to look for a good quality used one on craigslist or offer up. It's amazing how much money people spend on things like this, get minimal use and then they dump it for a fraction of the cost. When I purchased one for my kids we got it at GI Joes and was on sale for mid $300's. Look for one with a large glass style backboard and a stout pole with a large base. Ours lasted through my 2 youngest and then we gave it to my grandson until they moved and couldn't take it with them. Good luck.
@Orion Bailey don't you work for a steel company? Just get a nice plexi backboard and have someone at your work make up a support. I'm sure there are design specs on the interwebs.