I know I have had to buy whole figures for parts in the past. Once I was done with what I needed; I would split up the rest and sell to others who needed parts. It was a win/win for me as I ended up getting the money back in parts that I paid for the whole figure. I really don't see an issue with it. The demand is there and as long as bidders are willing to pay premiums for it; the practice will continue.
"The farther we go, the more the ultimate explanation recedes from us, and all we have left is faith."
~Vaclav Hlavaty