CJ PV 4 for $300?

Friend at work is offering a Conrad Johnson PV4 for $300. I ahve used it and it sounds pretty good....a little syrupy and warm but I like it. It woudl be a backup to other equipment or alternatively if it can be updgraded and sound good maybe it becomes a feature item. Comments on price or upgradability...anyone done that?
If Bill and Lew, two friends of mine, candidly, designed this and put their names on it, it's good.
As a back up, it's STELLAR.

Good listening.