Honestly, in my opinion, the advice you've been given here feels very reckless; an 80mg-165mg dose recommendation is just ridiculous. Yeah, sure, you won't fucking die, but seriously guys? This guy probably hasn't touched a stimulant in his life and you're recommending a high dose of a stimulant known to be very rushy, even intranasal?
What I would do (and do, if I use the stuff) is break half a gram down into 15-20 small lines and generally take two at a time, some times more if I let myself be greedy, every 20-40 minutes. I don't actually rack them up ahead of time, but they work out to around 25mg-30mg each. If you want to, just evenly spread the contents of your bag on a surface, powder it up well, then divide it in half by eye several times until you get your desired number of lines. You'll have to math it out, cause I'm not feeling very numbery right now.
Good luck
Edit: Ok, reading through your posting history you do have some experience with the white stuff. Still, 133mg is a heavy dose. Cocaine has a point when it becomes an unpleasant, nauseated, overheated mess. I guess we all have to puke after a line/puff at some point to really learn that for ourselves, but I really would suggest you just bust it down into five or six lines instead. Hell, even just priming yourself with smaller ones through the night, and finishing with a 130mg one would probably avoid all that. It's just senseless to dose all in one line all at once like that is all I'm trying to say.