They will certainly do their best to extort all they can. But then the government has to start being the arbiter of the value of everything. If I give you a piglet in exchange for a hen, what’s the tax? We could both claim the net income was zero since we obviously assigned equal value to piglet and the hen. If the dentist cleans the barber’s teeth in exchange for a haircut, who would know? This goes on all the time, as well it should. The more intrusive the tax man, the more devious people are in avoiding him.