I asked his same question a few weeks ago but go no replies.
I asked the seller a couple of questions and he seems pretty reasonable to deal with.
If you just wanted steel wheel turbo's, which run more boost without going chick chick boom then these are very reasonable for $1250 for a pair (exchange), which is a fair bit less than around $2,500 for N1's or 2860-7's etc (obviously these are much better turbos but they would want to be at double the price).
He also sells steel wheel rebuild kits for $330 or something but then you have to get someone to rebuild and balance the turbines for you.
If your used to a standard GTR these aren't going to be much lagier and will have better power (especially if over 1 bar).
Theres a guy on the forums Hypergear or something who rebuilds 32/33 gtr turbos to N1 specs for $660 each, which again is pretty reasonable.