Probably about as certain as you can be these days. Bought them at a reasonably well known Australian auction house that specializes in coins and stamps and sells stuff to a lot of Australian dealers and international collectors.
The fun in this case translates to doing a fair amount of research on the individual lots I was looking at and figuring out which lots provide reasonable value for the money being asked and contain coins that catch my eye.
I missed out on the lot that would have translated into "got them cheap". It was someone's world silver coin collection that contained a bunch of really interesting silver coins and some old Canada pre-confederation copper coins and tokens. I gave up against a mail bidder at $500 which would have been close to $600 with buyers premium. Due to a mix up, I was accidently listed as the buyer. I would have loved to have taken that collection at $500, but it would have been wrong. In sorting out the mix-up, I found out that the other bidder would have gone to $700, so I'm feeling less bad about giving up at $500 as I couldn't have gone that high. I think whoever the mail bidder was probably got one hell of a deal on that collection. Just wish that I had the pockets at the moment to be able to grab a deal like that one.