your choices as I see it are 1) do it cheap and illegal by contributing to the black economy. Pros cheap. Cons no guarantee no comebacks and risk of the law coming down on you 2) Get it done professionaly. From your description I would say that the quote you were given seems about right. Some may argue and may be willing to work for less. All things considered I am not. Pros guarantee and a come back if not satisfied. Confidence about who you have in your home with your possesions. Legal and above board. Cons. More expensive. Pays your money you takes your choice. Get more quotes get references check them verbally and ask to see the work ensure all quotes are written and have a full spec. That way you will see what he is charging for materials, what they are and how much he is charging for labour. Ask to see their liability insurance so you know that if it all goes pear shaped you know you are covered on the insurance. Bona fide pros will not mind. At the end of the day its your home, the single most important investment you will ever make, why take a chance with it, would you give the keys of your merc to a bloke in the pub that says he can cure that knocking noise.....probably not. I work my **** off as I have done all my life and to even go down the road of paying someone cash to save a few bob while my hard earned tax money is keeping them in their rent free house and supplied with fags and booze is an insult to all hard working people.
I'm with you about the Pols', I'm quite senior in IT and me and my collegues have invested alot of time in qualifications and are very professional. In 2001 there was a recession and IT jobs started to get scarce, at the same time there was mass immigration from Chec's, Pols, South Africans and various other non-eu countries which absolutely slaughtered the salaries, they came in under a fast track system because the government said there was an IT Skills crisis. There never was, they were under pressure from business who wanted to pay us less. I had to train even harder and get even more skills so that I could move up a few levels, just to keep my salary. Some of them were worth it, but the vast majority pretty useless. Salaries havn't really recovered and there is still an over supply of pretty poor quality IT people competing for jobs.
I don't mind paying a professional a proper rate, but I expect him to work for it, like you say written quotes, PL insurance certs, guarantees.
That said if a painters & decorators are like plumbers, who can't even be bother to turn up that I would rather pay a Pol.
The rate of about £200 per day is comparable to my salary. So if he has invested the years to be good at what he does then it seems fair enough to me.