Well there is this on store which name shall not be spoken had a 10g tank with about 20 common plecos and about 15 ADF's and there were about 8 plecos and 4 ADF's floating at the top of the tank and the plecos were eating them. 

a large petstore (pet city) most of their equipment would be half again to twice as much as anywhere else I've seen, fish wise while they have an excellent selection including (supposed) german imports.
Andrew