Wow, that's pretty hard to say without photos; but Miyatas in general are quality bikes, and most serious people know it. Vintage 80's Miyata 1000's in good shape will sale big in good shape, 600-1000. The 610 is the little sister of the 1000, a sportier randonneur version which is as desirable to the sportier old people who still value these bikes.(Such as myself) Most 80's Miyatas in good shape on the 'Left' coast would fetch 200-300; however, the 1000 & 610 are hot. I'd say, if it's in your size and in clean ride-able shape, if it sells for less than 300, I'd be very surprised. Especially in Houston.