Plasterer wanting cash up front

To be fair, if hes starting out, £200 a day is bloody expensive. I'd want a track record, time served plasterer for that.

Apologies if this sounds negative (again) but I've never understood people procuring services from someone who knocks on their door. Its like the pikeys who knock and say "We were just passing and noticed a problem with your roof. We can fix it for £100." Bill comes to several £1000s before they get nasty.
I'd ask your ex-plasterer for recommendations.