plan out what you are looking to get out of the car... if you need to go fast one or every or every other month then nitrous is a great way to go... if you plan on using this every other day then the cost of filling the bottle starts to add up and it may be a good idea to look into a low boost kleeman supercharger kit at $6,500...

nitrous done the right way is not all too cheap either... basic wet nx kit $400 + remote bottle opener $200 + automatic bottle heater $150 + purge kit $100 + wideband o2 gauge $300 + bottle fill ups... and thats assuming you will install it all yourself... throwing just a basic kit on there without the extras is dangerous (no o2 gauge to monitor AFR) and wasteful (no heater to maximize use of nitrous when it is near empty... no purge kit to maximize time gained)...
if you do intend on using nitrous i must suggest you use a simple circuit i have used on all my nitrous installs... utilizing a harlan engineering window switch + wot switch + trigger switch... i've written a short spiel on that somewhere on these forums or just let me know if you really want the exact setup explained.. it basically makes it so the nitrous only sprays when it is safe to spray and no other times...