Not all business owners, some are good at their work, bad at being an owner. it happens. lol
I see your points and they are valid. But just like with anything, some vets make people resentful, or feel over charged. It takes a long time to find a good match between vet and owner just like with patient and doctor.
But at the same time...not everything is as bad as it seems. I can't articulate well over the internet as well as i can in person. maybe i do one thing bad, but do in fact do some things for the animal well.
it's not uncommon for owners or rescuers to do a lot of their own stuff that they are able, just do to cost, and we're not talking trying to be cheap to be cheap, but out of necessity.
I also just spent 1,800 on my dog. But, at the same time, that whole incident i had someone new to the biz, and she did xrays without asking me, then charged 150 for the xray, and 150 (listed) to read them. I would have said no if consulted. So, she thought she was doing the best thing for a preventative measure, but she also didn't ask me history or even consult me, and if she had there would have been no need to jump to that conclusion.
But c'est la vie.
Many times i have found in this particular industry (and some other choice ones) that if people see you are willing to spend a little...they will gouge you a lot.
I took my dog to a vet years ago. He had been itchy since he was a 6 weeks old, my local vet said it was food allergies. did no tests. Just tried to sell me on science diet (which his full of fillers and not healthy food at ALL no matter what anyone says, ingredients are there to look up and are proof) and proceeded to try to sell me shampoos for his "dry skin" she saw. On my yearly road trip to oregon, i finally noticed patches of hair missing, and took him in to the vet there in rural oregon. The guy took a scraping, looked at it under a microscope, and said it was mange. Gave me the medcine, and actually told me not to bathe him fully with it, but sponge bath, and take the drippings and run them back over him so the medcine would last longer and not get wasted in a full huge bath.
Now THAT is a vet. That is someone who wasn't out to sell something, that vet was out to help and give care to the animal. (turns out he just has a lower immune system. is not allergic to grain)

When i took my snake in for the $200 gland issue, she knew right away what it was, and explained the whole thing to me. Showed me how to clean the gland, and expel the solid puss, as snakes produce puss differently than mammals.
I continued to learn about that, too for anything in the future.

As for treating at home. You are absolutely correct that since i had no experience, and since i was unsure, and wound up under-dosing, i shouldn't have done it.
however....every avenue i explored previous to that did not make monetary, or medical sense. I did not need the run-around.
I have had good vets and good experiences, so i also know when i'm being treated stupidly.
Which leaves the only option, home care.

So, i learn more until i can do it. In this particular case, under-dosing does not harm the animal (and one dose won't create a huge resistance to the parasites), so though bad, i did not really harm her.
Still may not be right, but i refuse to be taken advantage of.

I just hate the excuse that vet school is expensive so vets need to charge more. That needs to quit being said and more logical and factual arguments need to be made, such as like here...i am not a vet. You are right. *shrug* doesn't mean i need to be told that vet school is expensive so i should pay what needs to be paid according to some vet who owns their business and needs to recoup costs.

I've studied biology, and am still in school and learn more every day so i can go to the Moorpark Exotic Animal Training Management program. Will i ever have the knowledge of a vet? no. Will i be able to do some things a vet can do? Yes. I can now care for and clear an impacted musk gland.
And, despite how you may find more than me in a microscopic examination of fecal matter...i still found something indicating treatment was needed, and i still narrowed it down to a treatment that would take care of both types of parasite that it could have been.
Next time i look at least those will be out of the way, and i can look for more things. If i susupect i'm over my head i'll get help. But in this case there are only so many parasite eggs and dead parasites. I mean, you can see them. You can define them and match them. I did not perceive danger for the animal.

Anyway... i really am fine and not mad or anything. you're very good at articulating on the net! : ) I'm not..lol
i just don't like that one comment about vet school.
I'm still paying off my liberal studies degree (pointless!) and am going to school again.
But i'm pretty fair minded on this. When i make crafts or items others want, i factor in actual cost to me, time and profit margin. I do feel that many people do not do that precisely, instead they are motivated by greed and by when they see an easy target. it's an easy field to do that in. May not be nice to rationalize that, and it may feel like defense is needed, but the truth is...there really is *nothing* people can do about it when their animal needs help. It's either pay it...or the animal may die. It's not very fair. And there really are vets out there who ruin it for the good ones by knowing that, and consciously taking advantage of it.