A 3200kv motor powered by a 7 cell nimh with the stock Rustler gearing isn't going to be fast. Maybe 25-30mph if you're lucky.

Honestly I'd skip the nimh batteries and get some lipos. Brushless systems really need a lipo to bring them to life. You can get a decent lipo balance charger for under $100, and probably close to $50 if you just get a basic 50w AC charger. You can also find good 2 cell 5000mah lipo packs for around 30 bucks or so.

With a lipo and some different gearing your car should easily do 45mph with a 2s lipo and probably 60+mph with a 3s if you wanted to.