Makes no sense. How can you treat a barter exchange as income? If $600 worth of sex between two individuals took place, that logic leads to a total of $1,200 dollars taxed. What happens in case of a threesome, or an orgy? One orgy.
By the same token, if I am selling potatoes for US dollars, those dollars are my taxable income, but so are the buyer's potatoes. Does the buyer pay income tax on the value of potatoes? It's an exchange.
you assume the the fair market value of the sex I provide is $150 per hour, in which case my costs would be equivalent to my profits and therefore I would have $0 tax liability. however as anyone can tell you the fair market value of a male providing sex to a sexy female hovers somewhere near $0 per hour.
regarding potatoes, this is not a barter exchange. you are receiving the potatoes for money from some source of income which presumably has already been taxed. however there may be a sales tax attached to the transaction for it is not a natural right for me to feed myself and family from the division of labor in the society which I am a member of, and if government did not exist to protect sellers' property rights I could easily claim your potatoes as mine.