The way eBay is set up, it's meant to drive up the sale price by buyers bidding against one another. And yes, we're not the only ones bidding on straights (gasp!) so I don't mind people here bidding against each other, especially if it's a special or rare item
... but I don't mind if they make deals to, say, not bid against each other ... I'll lay off the Boker you want if you lay off the W&B I want ... and maybe it's a good idea to PM each other your max bids and see who 'wins', and then that guy can maybe get it cheaper (like Bruno said ... if he and I are the only ones bidding on a W&B, and he'd pay $100 and I'd max out at $90, there's no point in finding that out the hard way and letting the seller reap the benefits if a couple of PMs between us lets me know I won't win it so why bother and I'll concentrate on something else, and Bruno wins it for $10.)