but like you said, not well-informed. If you don't want to, or can't switch vets, I think that a vet that wants to help and is willing to learn is better than a vet who thinks s/he knows everything. Maybe you can tell your vet your concerns about her suggestions.
I did this when I first went to my vet. He seemed to be in a hurry, and didn't even suggest a fecal culture or float during the entire exam. After the exam, I asked to speak to him, and asked him what his expertise and interest in reptiles was. After he told me where he'd gone to school, etc, I asked, Then why didn't you order a fecal exam? It was like a lightbulb when on over his head. He apologized, and said that he didn't think Bud looked ill, but that he should have suggested it anyway. Now I work with my vet in Bud's care, because he realizes I know what I'm talking about.
I think vets are so used to seeing reptile owners who don't care that they get tired of giving advice that won't be followed. I have heard that reptile owners are the most likely to abandon their pets at the vet or skip out on bills. That's no excuse for not giving the best vet care, but I think when they see that you know your stuff and are determined, they'll work with you. Maybe your vet would be willing to borrow your iguana books and read up. In any case, at least you'll get some lab results.