a retailer puts up a job lot of TV's which have no reserve price with bid increments of £40, and then 10 minutes before the auction closes, someone bids for 25 units at £200 over and above the previous highest bid. Is that fair

It certainly is. You should have put your own bid in at "£200 over and above" if you had really, truly wanted one. Instead you got upset because your opportunity to go "bottom feeding" on the price got derailed by someone who was willing to pay what the items were actually worth. You had the opportunity to do exactly the same thing but declined.

As I have repeatedly said, an item for sale is worth what a willing buyer will pay for it. If the price is higher than you think is fair, then by all means refuse to buy it, and purchase a less expensive one instead.

tanstaafl.