depends on what you have done, where you live, etc.
i just took our birds in for a well bird/get to know you/get established visit with a non-certified avian, yet bird knowledgable and highly recommended, vet. the general exam itself was $50/bird, which includes a thorough physical exam, plus wing/nail trim.
we got blood panels done also, to establish baseline "normal" values for our birds, those were $~110/bird. we opted to get dna sexing done also, that was $70/bird (cheaper to get a card and drop of blood and send it yourself, but our vet won't do that).
the CAG also had another blood test (calcium ionization), which was another $50. total for first time visit, 2 birds: almost $500. getting results back within normal limits and finding out my birds are healthy: priceless
next year we will not need to do bloodwork, per the vet, and no more dna testing, so it will be much less expensive.
kris