The shop I worked for during that time period was a fair sized Miyata dealer, one that was consistently a Miyata dealer of the year winner. Every year we sold a handful of the Ridge Runners. They were expensive and weighed more than the tig welded bikes of the same caliber, however they were and still are my favorite brand from the 80's and 90's. The Team Ridge Runner was the icing on the cake as far as I see it.
To this day I still ride an 84 Ridge Runner, which is a very different bike than the 88 model. In my view, your Miyata is a super score, and top shelf desirability.