Board Thread:Questions and Answers/@comment-31614123-20170327194546/@comment-10336-20170328032728

They are also sold, I think, in JPN's Bazaar. Through Strawhat skulls are farmable at 3D2Y so buying them is a waste of TPs. Legend skulls may be worth it, if you cannot or don't chsoe to farm some tough events like WB Invasion (which I didn't farm, way too much trouble).