When proven breeders are being sold it does not mean there is something wrong with them, many times people will hold females and than decide at the last minute to let them go because they don't fit their project any longer, it happens, last year I started to let go of some girls simply because I am cutting down on normals who are being replaced by morphs and I did so at the very last minute.
Ask question buy from someone reputable and remember that regardless a 3 months minimum quarantine should be observed before any pairing.