JBL 2360 horns with stands for 150$ each in SF Bay Area
Altec 511b horns for 80$ for the pair.
The JBL 2360 is a fine sounding horn. Does 500-20Khz, even 350 with the right driver. You could easily build a 2 way with a woofer handling the <500 bandwidth. Ideally your space should be on the bigger side for these to truly sing. They are constant directivity 90X40, and many reviewers speak of the even diffusion of music. They are big though. I have the stands too.