Be competitive 24-7 — and bankrupt in 60 minutes! That’s how some British retailers are feeling after choosing to “auto-optimize” prices with Amazon’s RepricerExpress tool. An hourlong glitch Friday caused hundreds of items to be listed for one British penny, so independent sellers saw inventory fly off the shelves for nearly nothing. “I have lost about £20,000 overnight,” said one. Amazon managed to cancel some orders that hadn’t been processed, but it’s not clear who will foot the bill for the blunder.