Would never do. You won't have the full history of vetting
I’ve worked at an auction here in SA before. You select the horse you like in a catalogue and then have the option to view and try them. All horses should have up to date vetting a and you an usually ask any questions before hand. Once bidding starts it works like a normal auction 😊
Some competitions have auctions, they are really fun to watch, they are usually for younger horses and they talk about the horses features, then you start bidding, I don’t think it is a reliable way of buying a horss, but it is fun tobwatch