Like a lot of people have said, if you want to breed bettas, it's gonna be expensive. A real show quality betta isn't going to be cheap. There are some females that will be $15, but you still have to pay for shipping and even then, most of them aren't the best quality. There are also some local breeders, but I've still yet to find any with quality as high and unique as Thai breeders. So in short, no, you can't buy a show quality betta for less than $20. For the best, show quality bettas, you want to buy them from Thailand where they actually have regular fish shows and people actually breed them to standard. Aquabid and ebay are the best places for that. Most auctions have buy it now options where no bidding is needed, but bidding can actually get you a much better deal. If your seriously considering show bettas, you need to consider auctions. Bettas bought from other countries will cost you the fish price, international shipping price (usually $5), and transhipper price (somewhere around $30 for one, with huge discounts on multiple fish). Not to mention the tanks for adults and 200+/- babies, filters, heaters, live food, brine shrimp, almond leaves, water conditioner, thermometer, daily food, and possible medications you'll need to buy. Breeding simply isn't a cheap or easy hobby.