It depends on the tester. Mine charges $1 a bird each time she comes out.I do sell eggs, although not in Maryland. I think I may consider this anyway, if only for my own sake to know that I have no other diseases except Marek's going around. I don't mind the expense for the peace of mind it may give me. i have ony 16 birds left out of 18: one rooster got harvested, now this hen culled. So it wouldn't be a major expense if it is $4 a bird.