I believe £6k in an individual month could be achieved - though I've never come remotely close. As for repeating it every month, I suppopse it might be possible if ignoring the winter months if ALL the work was VERY well priced, no messers, no glitches. Personally, I prefer not to end up having artificial joints fitted to my body. That may end up happening anyway but I don't see why I would want to encourage it.