It's on a Saturday, so traffic shouldn't be a big deal. Prices in SF and South Bay (MV/Sunnyvale/Cupertino) tend to be similar. So it's really up to you. But SF

It's on a Saturday, so traffic shouldn't be a big deal. Prices in SF and South Bay (MV/Sunnyvale/Cupertino) tend to be similar. So it's really up to you. But SF does have a lot of options for budget hostels (outside of the hackerhomes that are available on AirBnB). If you have the cash, I would rather spend it on a nice place in South Bay then on Uber.