Are you really sure that it is the Grd2 you want? The Grd2 seems to be the least liked of the three GRD models. The reason for that is basically the horrendous NR of jpegs which turn it into a raw-only camera unless one is prepared to stay at base iso and iso 100. I don't remember if the NR began to show off already at iso 200 but it certainly do so at 400.
Also, the phase-detection AF was removed with the Grd2 which slowed it down a little bit. There is still snapmode of course though.
The GRD2 is the unloved one in the family, and I did upgrade to the GRD3. The GRD3 has much better high ISO performance, including a usable ISO800 for colour. It also has the faster lens. Since I use my GRDs for shooting bands in clubs, these improvements were important to me, and I don't regret the upgrade.
It also has usable autofocus, which I do use from time to time. But frankly, using either snapmode or manual focus on the GRD2 was not a big pain. That is not to deny that autofocus on the GRD2 was pretty awful. It alone would not have been a reason for me to upgrade though.
I missed buying a GRD1, opting for the 2 as I saw it as being better for colour, as it had decent raw performance. The GRD2 may not have the filmlike look of the GRD1 for black and white, but I have an 11 x 14 enlargement from an ISO 800 jpeg (braincramp led to raw+jpeg being off) hanging on my wall. I used the GRD2 extensively in Paris and Buenos Aires, and I have exhibited prints from it, and I don't think any were shot at ISO100.
I do love my GRD3, but if I hadn't bought it, I would have continued to be happy with the GRD2. I don't know the seller in the auction referred to in this thread, and obviously don't know the condition of the camera -- but the price being asked is pretty good provided the camera is in good condition.