If something interests me, I'll put it in my watch list. At any given time, my watch list is 20-30 items but I may bid on 0-3 items per month. But win I do bid, I win 98% of the time. I nearly always only bid on something I have an immediate need but every so often I'll bid if it is a crazy good deal (the last one was a right side only open C shifter for $12 delivered, I couldn't pass it up). I occasionally will flip an item if I get a different "better" one. Knock on wood, but lately I have getting a pretty good profit from the flipping, even with the crappy dollar. And I would say in the last 6 months, 90% of my purchases have been from international ebay sites.

I only snipe and if I am not available I use ezsniper. I usually determine a low end value and then add and additional 20% to that number for my final bid. $8 in the grand scheme of my life doesn't mean much versus the disappointment of losing by $8. For things I must have, 1-3 per year, I'll put in a way over the top high bid, damn the "value" and that stuff I'll keep until the grave.

I find holy grail items for "cheap". I just won a prewar aluminum Ambrosio stem, far rarer than a Cinelli steel stem and it was $40 delivered (there also were some bars included, but I wanted the stem). $40 may be a lot for a stem, but not compared to the $100+ steel Cinelli.