Just a sign of the times.
Most of my tv repairs are sets I have bought as faulty, repaired, and sell again (or if I can't repair it I strip the set and sell the good panels)
What seems to be happening is the price of working second hand sets is falling, to match the drop in new prices, but it's getting harder to find worthwhile faulty sets to buy. Prices of faulty sets are still holding up.
I used to buy fix and sell sky HD boxes, but that market went the same way, to the point you could often sell a "faulty" box for more than a working one.
Currently the only sets I can find cheap enough to buy are small (sub 19") sets.