Beautiful bike. Agree with
Bianchigirll . I'd sink as little money as possible into the consumables since the buyer will likely want a different saddle and may well want different tires.
Price is obviously location specific. I live in a middling city in the midwest and locally I reckon that bike, even overhauled, is worth around $450 but this is a tough market to sell a quality vintage bike.
I'm a big Miyata fan. This is, IMO, one of the best production vintage racing bikes you can buy.