Yep. More often lately. I bought an £85 ticket for an O2 show which was equivalent to the ones they were knocking out for a fiver on the day before.
You take your chances now, you can guarantee the type of ticket you want and pay face value or risk waiting it out and pick something up nearer the time. Only the very best tickets will be more expensive on the secondary market.

Its much like having a bet in the morning on a horse at 5/1. You take the odds at the time and if it wins at 10/1, thats your loss