This is pretty amazing. Technologically easy but "Who would have thunk it?" is my reaction.
Buy-It-Now is certainly my preferred scenario both as a buyer and as a seller, and this makes it happen for both parties.
As a seller, I want to make what I can, realistically, and I want the sale to happen as quickly as possible so I get my money soon.
As a buyer, I want what I want, at a "fair" price, and I want it quickly without tension or interference.