No, not only for the rich, same as cats. Our little Minnie (cat) cost us a small fortune in the months before she died - but until then the main costs had been annual boosters. Evened out over her life of 15 years it wasn't excessive - it just seemed to come in lumps.
Tyke is, so far, just on the jabs. I agree, though, that vets' fees do seem huge when all they do is a quick check and a booster jab. The P.D.S.A. is one of my preferred charities, perhaps you could try there for more reasonable costs.
Appropos earlier points - there are horrible things go on overseas, our dog is a French rescue dog (because we lived there) but I would say that there are dogs in deep need in the UK, so start there first. As far as I am concerned the R.S.P.C.A. is a slaughter machine, I haven't contributed to it for 40 years - rescue one from there if you can. Small rant over. :)