I figured that mate from your previous posts, that's why I reckoned there had to be a reason. I still do think that getting some RPM behind them will help with the not-snapping.
Yeah that's a fair point, however I don't want to get carried away and end up going too far.
I've messaged that guy on ebay from the link that kram posted. He says he can't do much on price.
I think i'll end up going with the £30 set from screwfix as it works out the cheapest by far. And I'll have enough that I can just throw the bits away when they break or get blunt... It'll probably last me for the rest of my life! I have a good set of Dormer drill bits for the jobs that matter, so i'm not too fussed. Thanks to everyone for the help!