it depends, i am not a pro at this but i think i can help you price it out.
10 gall tank 10$
lighting for reef 125$
stand/powerheads100$
sand 25$
live rock 65$
(live rock averages 6.50 per lb and going at 1lb /gal it would be better to get into the 15-20 lbs)
salt mix/accessories like thermometer... 40$
anything i missed + eventually purchasing coral and fish are extra. also there are some wonderfull prefab nano kits like the 12 gallon eclipse, is what i have, needs a lil work like upgrading the lights,but its nice, also theres the nano cube 12 g andthe come marine ready with good lights and filters and all.
all in all get 300 bux together and youll get it done right