I wouldn't say it was a mistake. I also wouldn't say it was a very good deal. You basically bought a 4 year old bike for near the price of a new one with the same specs. Here is the basically the equivilant of that bike in the Trek line.

Gary Fisher is owned by Trek and there bike lines are very similar on the low end. The component groupos are basically the same between the two bikes. So, you could have done better by going to your LBS, because you could have gotten a new bike with local service at nearly the same price.

With that said, you still have a nice bike coming. You didn't waste a LOT of money, so forget it and enjoy the bike. Next time, you might want to do a little more homework first.