Looking at the budget for Wikipedia, I can not see a headcount cost. There is hardware and bandwidth costs, which should be very similar to the running costs TPB had when the trio ran it.
The question here is what the running costs of TPB is. My point is that those should mirror quite nicely the running costs of Wikipedia, since neither has "headcount cost" attached to each visitor. Both are mostly just serving static text on a website, and neither are paying royalty or click-throughs to third-parties based on visitor count.
In revenue, Wikipedia has donations and TPB has ads. Asking which revenue is bigger is very different from calculating costs. TPB might earn more revenue, but to figure that out one has to calculate the competitive price of advertise space for infamous websites. My guess is that the competitive price is quite low, sine few companies are willing to send untraceable money in order to advertise on a website that many companies and governments consider criminal.
So for revenue, I would look into what botnet spam and hijacked webservers brings in per eyeball. Multiply that with the visitor count of TPB, minus the running cost, and you should get a rather realistic number for the sites total income.