As long as you want a 20K bulb it's probably a good deal. I see it says "like new", which I assume means the ballast, but 1 of my mh
ballasts is over 15 yrs old and fires up like a champ. So with the 2 yr warranty I think your OK.
parts list to buy seperately:
20K 400w bulb aprox $60
ballast aprox $35
new reflector aprox $25
Going by that short incomplete list, yours seems like a good deal.