Is there an IDX API demo server that application developers have access to?

I would recommend becoming a reseller for a company like HarBeck Software. They have a good MLS Search and will let you market and resell it for a good profit. You don't have to do any programming or support. The MLS Search is ready for your customers in 2 days.
www.harbeckhome.com or 866-HarBeck. I've worked with them in the past.

Infinityman