tbh i always say that you should prepare for if they dont sell, thats the attitude i used to take as there are no garentees. if you have quite a lot, its worth maybe thinking about haveing a table at a show.
as for price, tbh at the end of the day its entiarly up to you have much you sell them for. though the lower in price the more likely they are to sell, yes there might be some breeders out there that wouldnt be to happy, but its up to you weather you under price them or over price them to be honest.
tbh there is no money in breeding leos, not unless you have the money to invest in some of the more expensive morphs, but then saying that, how many people at the moment have the money to buy an expensive morph? i say if its what you want to do then go for it, long as your prepared for the what ifs if that makes any sence?