I have noticed this on ebay and yes cheap because it is cheap, I think it has finrot or something is wrong with it look really close to the fins something is wrong. Hmm look at the top of that picture and the back fin at the top is that a deformity??
these are questions you should ask yourself, especially when the price is cheap. I was just at my lfs talking to them about there bettas and the ones I breed where they come from thialand and are halfmoons wild type so they would get f1 strain, thing is I have money makers they don't and they openly admitted it. So they offered me a good deal on some because they want some and they said to me we don't want the crappy one so name a price. Basically I could sell them the ones that should have been culled easily but why, they know and understand the quality and willing to pay! See what I mean by difference? The price is secret between me and him and mainly they buy in bulk and take the loss, but not in this case when they know I will raise them all strong no matter what and they know my breeding style of culling hard