Oh yeah, that's an interesting solution.

I'm not sure simultaneous authorization and anonymization is impossible. Couldn't you use something like Chaum's e-cash to obtain tokens that guarantee the holder the right to use the network for some amount of data, but these tokens are tradeable and therefore the spender doesn't have to be the same as the buyer. Then you could spend this token in the network to get access and the network could authenticate the token without identifying the spender. I'm guessing something like zcash could be used as well...