about to buy a 1990 sub

[jjkamikaze]

My watch guy has a 1990 submariner with no price but an appraisal for $4500. This watch was worn hard and the case, bezel, and bracelet are very scratched. The crystal is of course scratch free. There also seems to be a fair amount of dust under the crystal. There is no service record but the watch seems to function. Should I avoid this or make a low offer? If making an offer how low should I go? I'm fairly certain he got the watch very cheap since he operates what can best be described as a jewelry pawn shop and gold buying.