The Univox hollows are well built with nice fit and finish, and the hardware is solid. The Matsumoku factory knew what it was doing. IMO their biggest weaknesses were the necks (prone to warp) and the pickups/electronics. I have a gorgeous Univox hollowbody waiting for a pair of Gretsch Filtertron pickups....and as usual with me, everything else gets in the way.
That said, I think the one in the auction had a reserve set too high. They're a good $200 used bass, not a good $300 bass. For that $300 you can pick up a number of the Ibby Artcores, which are very nice indeed.