If it is good quality cocaine, a gram for one person is more than enough for one night.. I could get 15-20 lines out of a gram of good quality cocaine, which would last me 2-3 days.. Now if you get shitty cocaine then a gram may not last that long..
Just start small by doing a small test line to gauge the quality, and go from there. Try and leave 45min - 1hr between lines. Doing too much coke too fast is not a good feeling.
This isn't really OD material, so I am going to close this.. Please check out the OD Guidelines & Posting Standards, conveniently located in my signature. Feel free to PM me with any questions regarding the rules.