Nitrous usually runs about $3.75 a pound. The bottle holds 10lbs. of nitrous. You usually will not run it completely empty. Maybe about 2 pounds left whenyou refill. So, you will be paying for 8 pounds of nitrous. About $30 to refill.
Depending on what horsepower setting, 50 shot will last about 15 passes. A 75 shot will last about 10 passes. A 100 shot will last about 7 passes. A 150 shot will last about 5 passes. My 300 shot on my Vette last 3 passes.
I've used up to 3 bottles in a week in my Nissan just playing around. It can be expensive. My bottllle is right behind my drivers seat where I can get to it TOO easy. Put it in the trunk so you don't become an addict!!!! Harde to get to= less likely to use all the time.
Seems to me it would be much more cost-effective to do serious (internal) mods. Well I know I wouldn't have the discipline to keep my finger off of the "fun" button. So that little Nitrous fantasy is out of my mind then, lol!