Looks like a nice example at a nice price for sure.
The 8980 (and 8981) were the first of this series and I think were made from 1982 or perhaps a year or two earlier. Anyway, the long serial number will put a date on your example - first number for year, 2nd and 3rd number for month.
Citizen updated the assembly for later models in this series (8982 8984 8986 8987 8988 8989) by moving the T sensor off the glass face and onto the bezel below. The LC panel was then extended to use the space vacated by the sensor. The different model numbers in the series denote different colours / dials / LC panels. As with the many 894x series Citizens the guts of the movement remained pretty much the same. The ones, as yours, with the sensor on the glass are the earliest ones of the 898x series.







