I got a used Rans Stratus XP for $300 on craigslist. It's a long wheel base and rides like the Queen Mary. It was probably not ridden for a few years as evidenced by some rust spots on some of the bolts. But some elbow grease and it runs and looks like new. Changed tires and added an 11/46t cassette for our hills.

I used to build my own recumbent frames back in the 90's and 00. At these prices, it's just a lot cheaper and easier to buy used. Looking at a short wheel base Rans V rex right now for $300. Key is to be patient checking craigslist. I'm in the Bay area so we might have better supply here.

Hope u find one.