I'm not sure what the lag time is on the aggregators--but it's noticeable. If you're "stalking," you might first check / bookmark one or two broker's pages as you'll likely have a half hour or so to make an offer before others see it on one of the aggregator sites. As for last night, that the best price for CCV all hear would be on the site it was one was nowhere on my bingo card at all. So that strategy wouldn't have helped me at all yesterday--plus I'd have to wade through endless dumped Aulani contracts, on Haloween night, to find it.