Ew, slavery shit... though it seems like the protag ultimately isn't going to be following through with actually purchasing and is instead going to have to escape alongside the dwarf gal.
Still remarkably gross how they were legitimately going to make that purchase though.
So your butthurt is entirely your own fault, gotcha. Also, gender-bender yuri is far from common, and doesn't do anything to mess with the "purity" or "vanillaness" of Yuri any more than the Harem tag would.