Interesting how many of the bidders have only ever bid on a single item.....
But, yeah, someone wants it bad....:P
All that has to mean is they don't bid on the common, listed every day or week junk and wait for something that is truly rare. Look back and see how many K152's have ever been listed on ebay, bet you could count them on one hand. That said, I think it's a bit much for the wrench, they've sold for more at MVWC auctions, but $525 is about $200 more than I figured ebay would support. I have my eye on a K152 in PA if I can convince the nice little old lady to part with the last of her late husband's modest little collection.
Actually just looking deeper into it... 10 unique bidders and only 3 only have bid on that wrench in the time frame ebay shows. That's not to extraordinary.