You buy TCGO codes? I just found a tin full of them today... there must be like 300 or so in there, all unused. How many do you want to buy? I believe that most of them are XY, if there are any tin codes I find in there, I'll let you know.
EDIT: I found two Xernas tin codes, one Fennikin deck code, and two Chestnaught tin codes. I believe I have more tin codes, but I'll have to search around more as they are not in the tin I found.
EDIT: I searched the rest of my tins, and found one Sylveon/Noivern deck code and one Black Kuyreum tin code. The others I must have thrown out or given away.