Probably the two hardest things to come up with are time and opportunity when looking for better guns at prices you can afford.
It takes patience and sometimes long waits. But you also need to see lots, and the more of them first-hand the better. Garage sales, estate sales, want ads, pawn shops, gun shows, neighbors, and word of mouth are your friends, but they all take time and patience to track down.
Pics are one thing, but the feel on your shoulder is better by miles. In my experience it's just a whole lot easier to decide a price is "reasonable" when you have a gun you really like right there in your hands. The opportunity to dicker is better face-to-face than on line.