yorkies are worth a lot because of the demand of this popular breed... therefore ppl will pay a lot for it. there are many yorkies in shelters but not a lot.. i check my local humane society and there are never any yorkies there.. from what i learned, smaller dogs tend to get adopted the fastest.
i dont think its anyones business inquiring why a person pays as much as they do for something... i could ask the same thing about like cars, jewelry..etc.. but i dont because its not my business on what a person spends their money on. life is short, and if you really want something that you can afford then id say go for it!!