Depending where you live. I just had my flock NPIP tested and it was free. The state has a grant.
Here in NC the fee for NPIP testing is practically free: $5 minimum and $0.10 per bird after that, I think. The trick here is actually getting them to come out. This year worked better for us than previous years when they came out once then never came back again, despite repeated calls.
If I recall, at shows they charge a dollar minimum...or a dollar per bird. Don't even remember b/c it's THAT paltry. LOL