use the 20's for something youve never done. try a planted tank or nano SW. (dont know if you ever did those just ideas!) or if you have other housing for the fish turn them into w/d's for your new tanks. But i see your in TX and really you wouldnt get much if you tried selling con's. IF you could even find a store to buy them! there pretty common here ( at least in North TX) There awesome fish but if they breed it is cheap feeders just remember to keep there diet balanced. Where in TX are you , ive never done a build like that but would love to help!! im in Lewisville (right by DFW airport)