Dr Johnny Fever
RIP Grizzly 399
Well on Gametime I believe you buy the tickets straight from them. Not sure how their fees work.
714 (no fees) has them as cheap as $15 for uppers.
Stubhub has them as cheap as $8.
They are only the conduit, they don't own the tickers they sell. It looks like brokers and teams themselves may be supplying the last minute tickets. The owner of the SF Giants is a partner in the venture. Other investors are not being divulged.