I've no problem with "paying up" for a good job, well done.
I do have a problem when neither of the earlier jobs were done properly (the 1st adf went u/s within a week and the KX155 was unuseable for 2 months because said firm couldn't be bothered to adjust the side-tone correctly).
I have a big problem when I discover that I had been charged double what most other organisations charge for their labour, simply because I was too naiive to check out their quotes. My fault, I realise now but, with this particular outfits reputation, it didn't occur to me that they were simply 'helping themselves'.
I agree with the adage "if you pay peanuts, you get monkeys" but, in this instance, i've paid a premium and got robbers.