yes, you can buy a light if you want to , safely with a credit card...I would go to site of choice and get toll free number and call them up...this assures you of getting everything you want/need and it cuts down shipping time...here are 2 sites, that i have bought lighting equipment from...bghydro.com......and 4hydroponics.com....
alot of people buy from insidesun.com(refurbished) and I have bought a 250hps and a 400mh off ebay...both for under 80 bucks each and a bulb upgrade of 70 bucks for a 400w sunmaster warm deluxe mh bulb.

Are you handy? If so, then you can by a ballast kit chords and mogul socket + a bulb from bghydro.com
and put it together yourself! They will even talk you through it, if you get stuck...goodluck