The initial, and most important question, is how experienced is this vet with rabbits? A follow-up question, which arguably can be equally important, is if you are hesitant to trust this vet’s judgement and are not entirely comfortable openly questioning their judgement during an appointment, is this the right vet for both you are your rabbit?
Vets misdiagnosing rabbits is very common, because one symptom can have so many explanations. “My rabbit has small poops” can be related to poor diet, parasites, stress, teeth, a digestive disorder… there’s a lot to comb through and consider, so a rabbit-experienced vet (exotic vet) is key for correct diagnosis. Additionally, feedback and input from the owner is important too. Providing what your rabbit is like at home, your observations and actions taken, etc.. If you’re not comfortable voicing those to a vet or a vet is dismissive of it, that can also be a sign that the vet is not suitable.
I am not experienced with ear mites or ear infections. I do know that lops are more susceptible to ear infections because of the lopped ears. Dried pus can take a form that seems like dried skin flakes. The charges are normal; exotic vets are specialized, so vet bills are generally higher.
If you’re very concerned, I’d go to another vet for an additional opinion. It would probably be wise to still do the treatment and see if there’s improvement.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.