Bengas do you have two standards of work then, one for customers you are making a mint out of and one you are not making as much out of.
2 rates.
One reasonable, not cheap, not very expensive either, always relative to other quotes I hear.
The other one is a zero rate for jobs that I do as a favour for whatever reason.
The quality is always pretty much the same.
It is not a matter of slagging off cheaper work, but of exposing inferior jobs for what they are.
If somebody wants to try their luck and go cheap, they have my blessing. And it is not impossible to get a cheapo job done which works fine for years, though I wouldn't count on it.
What I don't like is cowboys pretending that they just earn less and do an equally good job whilst using inferior materials and cutting corners on the workmanship.
I have yet to find an installer working in the same area who provides good quality for significantly less money. He will have the same fixed costs, the same amount of time lost in traffic jams, the same costs for parking and so on and so forth.
And you simply can not do a quality install for only a few hundred quid, unless the system is clean, all the rads and valves fine, the gaspipe big enough, and you can just take the old boiler off, and stick the new one in.