Per Kurt Huget, house took $1,418.50 for the night, though it's a little hard to read. With ca. 200 @ $2.50 admission, that would suggest that every attendee bought $5 in drinks and whatever food was on hand. We do note that Garcia's guests included Rex Jackson +3, Dan Healy +1, Marmaduke +2, and Kidd +1, so big bar take might make perfect sense.
listing: "Who's Playing Where," San Francisco Chronicle, August 4, 1972, p. 52
listing: San Francisco Examiner, August 5, 1972, p. 8