If I understand you correctly you are vaccinating just every 3 yrs right? If that is the case then you shouldn't have any problems adopting. Most vet clinics have found that the vaccines can last longer then just a year now some lasting 2yrs and others lasting 3 yrs.
I take my babies in every year for their annuals too both canine and feline, just feel better then just taking them in when they need vaccinations.
Yes the adoption fee sounds about right. Best wishes to you in finding your new family addition