uh well , the thing that most people run into with coke is comming down. Now , if you get a gram , instead a stretch it out over a week (which I doubt you will do ) just make a night of it and have something in hand that will help the comedown so you don't go out and get more. Most people would suggest benzos ie valium , klonopin.etc and those are great , i would personally get some narctoics for the comdown such as percocet in your case , oxy,hydrocodone , heroin.etc but those are addictive as well so if you wanna avoid getting into that then just have enough to give you a nice rexlaxed high as the coke wears off.
If you have self-control then this plan should work for you. If you have no acess to any of these then take an otc sleep aid or marijuana which isn't as effective but is better then nothing.
Honestly , I can't think of anyone who would stretch out a gram of coke more then a day or 2 , its usually a night thing.