My vet is worth every penny. He doesn't make unnecessary charges for things like blood tests unless I request them, and he even let me buy wormers online to take in for him to administer when I had dogs going abroad. Yes he does make a fair bit out of me, but if an animal needs treatment they get it. It costs them a lot to set up and run a surgery these days, and I find the smaller 'one man band' type vets are much better than the large chains that have taken over a lot of surgeries in recent years.
I could not afford to take our insurance on all my dogs, and in any case I would not have been able to claim a penny on my vets bills as they have been either under the excess or for routine treatment such as neutering or vaccinations. Find a good vet and stay with them is my advice. One thing that always makes me smile is that people moan about the cost of vets bills yet there are so many overweight dogs! If people cut down on the amount of food they give them unnecessarily they will save money!