W3's aren't bad subs but I don't really like JL. Subs that are used for half a year I wouldn't consider bardly used though... listen to them and if you like how they sound then offer him something a little less. Do you have anything if your car now? If you do then hook them up in your car and see how it sounds... remember every car will sound different.
Someone about said something about the W7's... personally I think they suck. For the money you could get an Eclipse sub and blow the W7 away. If you are going to spend the money for high end JL audio subs then go with the W6.. but once again that's just what I think.

97 RS- Runs, but never driven
2000 Subaru Outback- Daily Driver