Going to be in town with a (let's just say VERY) cost-conscious group on Saturday night, but would still like to have a halfway decent San Francisco experience without pricing them out.

Any recommendations in the < $20 pp all-in range? (Not McDonald's TYVM)

There will be 5 or 6 of us, so maybe someplace where one big dish can be spread across more people to get more quality over quantity?

Thanks for any ideas

I assume when you say "SFO" in your title you are looking for something near the airport?

I think that may be possible at Osha Thai.
http://www.oshathai.com/
Their portions are large, not really family-style, but "sharable".

Title says that but the text suggests the opposite.

On Clement Street, just west of Park Presidio (SR 1) there are a whole bunch of inexpensive Chinese, Russian, and other types of restaurants to choose from. Fun places to wander around and then finally choose.

Can't go wrong at the following places:

Pasta Pomodoro (several locations, the Irving St and Richmond District are easiest for groups) I love it - choices of pasta or mains and nothing over $20

Depending on your bankroll- Ma Tante Sumi in the Castro has a neighborhood dspecial every night - 3 courses, $23. EXCELLENT bistro fod - make rez for a group on a Sat night. http://www.suminthecastro.com/

nearby to SUMi and even cheaper - upscale cafeteria of Thai Chef - great thai food but what really makes it is the great service.
https://webpos.wlinformation.com/thaichefsanfrancisco/

Another great Thai - Cha Am at 3rd and Folsom - elegant decor, service is OK, and the portions are good sized. chaamthaisf.com

For REALLY elegant thai - Basil - make rez for a Sat as they will likely be crowded - cool fun drinks as well, more suited for family style than the others. www.basilthai.com

Lots of chinese places would work (look at chowhound.com)