I just dropped by AquariumWest today because they had a new big shipment of fishes that came in on friday. They have drop dead gorgeous platinum whites and dragonscales. Unfortunately I was in a rush because of parking meters and all so I couldn't take pictures of them. They were literally solid white platinums. Many places claim to have white bettas but they werent solid white, a lot of transparency or mix with a shade of beige and all. But these are literally white. 30$ for crowntails and 40$ for halfmoon ones i believe. Theres also dragonscale betta selections for 50$. There is also some platinum white halfmoon betta with the body being white but a lovely blue on all its fins.
Just wanted to point that out there for the betta lovers that would like to seek bettas. Though the price is fairly high, those bettas are extremely nice and its worthwhile if you are really into bettas or you want to add a special centerpiece to contrast your tanks.
Just to note that they don't always have these special coloured ones, they usually have a betta order sheet and ask people for what they would like more of from that list and they order it into one BIG shipment then have it sent to the store to sell.