I absolutely agree with those saying quality is worth paying for. But I've still really struggled to get myself to pay £20+ for a pair of socks. Or even £10+ really!
I happened to visit GoOutdoors today, so while I baulked at the Bridgedales, I have taken on the mention of liner socks above, and bought a 2 pack of Peter Storm Coolmax liners for just under a tenner. We'll see how I get on with them, and if they're good, I'll go back and empty their shelves.
I wimped out of the thick socks quest because there was just too much choice, and they were all loads of money.