In particular, it seem to me that people should note...

Buyout clauses are like the very high buy-it-now price. No-one in their right mind should start with them. But unlike on eBay, bidding at a low price doesn't mean they vanish. An unlike on eBay, clicking on buy it now doesn't prevent someone else bidding anyway.

Sniping an auction with a 1p better bid 50 milliseconds before the window closes doesn't work as well in football as it does on eBay.