Well, I would check the year, cause Trac apparently ceased manufacture in 1987....and a Mint 1987 is worth $475.00 US.
(Confirmed Blue Book Value)
They may have continued to market, however, in which case if the VIN plate verifies as being a 1989, it would be worth about $510.00 US in mint condition.
(Estimated Blue Book Value)
Trac uses a Batavus-style engine, with an Encarwi Carb and many of the parts are still available, not that you apparently need them, but it's good to know.
If it were me, I would not let it go, Trac is a very "classic" design using much the same frame and style in the 80's as they did back in the 60's, so it has a very retro "look", and if it's in nice shape, keep it - ride it, and enjoy the hell out of it.