Hello!
Firstly, sorry I'm a little late to seeing this, but I figured a response wouldn't hurt. Anyhow, you may find yourself in a bit of a "cycle" when it comes to breeding the Malawi cichlids. Approximately 5-10% of the varieties are considered "common" and are the colors and strains that one can usually find in
LPS or local/online breeders. They are usually the most eye catching, and because of how common they are, they usually don't fetch the highest prices. The "rarest" varieties are usually the most dull-looking varieties and don't get as much attention and their more colorful counterparts. However, if you still would like to try, Malawi Peacocks and Malawi Haplochromis varieties walk the line of colorful and price. They won't fetch an extremely high price (in comparison to discus, for example) but the larger sizes (3-5in) could net you $30-50 depending on their strain.
Hope that was somewhat helpful, and good luck!