We must be lucky Lynn, our vets do give us discounts, both mine and the rescues (mine was only cos I asked for it though, it was to help out when I didn't have the car), and my vet does work with me when it comes to my own cats - although seeing as they get anywhere from £500 upwards from me each year, I suppose the odd free consult is nothing!!
I agree with Susanne that I dont mind paying a consultation fee, although I have been shocked at it in the past, I went for about a year with having it included with other stuff, so when I had that by itself, I was shocked at £20!! They do have to pay for wages, rent, electricity, etc and that money has to come from somewhere.
As for places like VetUK, I did ask the rescue's vet about this, and he said they couldn't charge any less than they do, as they can't buy in bulk as much as those places can, plus less overheads, so they can't compete. But, you always have people who have pets and no internet access, so they will still get the custom - I know all the staff at my vets buy them from the vets, despite it being cheaper on line.