Possibly not, if it allows society to turn its back on the underlying problem, either moving the trade underground, or forcing people in dire circumstances to resort to worse remedies. But I also think part of our unease has to do with what we perceive as an unequal exchange. The seller is giving up part of her body in an irreversible transaction.
The buyer is giving up only money – perhaps earned on a lucky stock trade or through an overpaid job. If that money was earned by selling a portion of a lung, or by painful savings accumulated after years of backbreaking work, we might consider the exchange more equal. But the central virtue of money is precisely its anonymity.