I think you can probably pick up the power button for around £2~ incl shipping (I think its more likely to be something jammed in it though), with the tiny screwdrivers costing probably £5 (I got mine for free with a new LCD)
I've had a cracked screen, camera wasn't working, no sound on videos etc etc. They're really easy to dismantle and reassemble - plenty of you tube videos to help as well
