Thank you guys, i bought a powercolor rx580-8gb red devil off overclockers for less than £325 new with 24 hour delivery, thank you for your help guys.
Prices are dropping quite severely now. I saw a 980 sell for £150 yesterday, and there is a flood of mid £400s 1080s too. Apparently the value of coins has dropped below the cost of leccy. I think we are starting to go over the hump now.
Might push out the causal miners, but I'm confident that you will still have lots of: 1) places where the elec is cheap / free to the miner 2) those that are thinking that it's going to balloon, so best to keep on trucking.