should i buy this?

i know someone who wants to sell me this system for 600 bucks, i dont know much about nitrous except that it is the NOS 05176
and comes with a couple of extras like a bottle warmer and remote bottle opener. do you guys think its a good deal or should i hold out for something else? thanks
here are the pics

http://images.cardomain.com/member_images/3/web/339000-339999/339223_75_full.jpg

Used nitrous systems, are always a crap shoot on the solenoids, but the price on this one is very attractive with all of the accesories, I'd buy it.