Aw, shucks, ain't nothing...
Actually, what I look for is Canadian sellers, first of all, since a lot of Canadian sellers don't like Paypal (nor do I) and they're willing to do the money order or cash thing.
I always check the shipping cost first. If it's acceptable to me, I then check to see what other items are being sold by the same person. If there's anything else I like, then I check to see if the seller will consolidate lots in the same envelope. If he's okay with that, then I'll bid on the lots I want.
The guy in this case is in Nova Scotia, and what tipped me off to him is that I wanted to buy a groat. He had a nice one from 1838, with a low opening bid of 99c, but it wasn't coming up for a week. He offered low shipping, and in the meantime, I checked on the consolidation issue. He was fine with that, so I checked to see what was coming up before the coin I wanted.
He had a lot of Indian quarter-, half- and full rupees, all silver, all with a low opening, from the early 1940s. Beautiful, all circulated but very nice with little wear. I waited a couple of days, bookmarking his page, checking every so often to see what other interest there was; for some reason, there was little.
So, I bid on the Indian coins the day before they were coming up, $2 maximum on the full rupees, $1.50 maximum on the others, and I kept checking back. No other bidders, and I got all six coins I was bidding on for 99c each.
I still wanted the groat, coming up four days later, so I sent him a note after he invoiced me, asking if we could just let my tab ride another week or so. Again, no problem.
Last night, the groat came up, along with some more silver Indian coins, and tucked in right between the two was this '42 Merc, so I bid on it too with a $2 maximum, and some banknote lots, all about an hour before they came up, as the Missus and I decided to go out for coffee. When we got back, I looked to see what the results were.
I got every lot I bid on for 99c -- the Indian coins, the Merc, and the banknotes --BUT NOT the groat, which wound up going for two bits over my $3 maximum bid.
If I had been home, I probably could have won it too, but that's the way it goes.
I guess you can't win them all, but I think I did okay.