There were two runs in the 1980's. Both had the regular (not lugged) heavy barrel. All that I saw had square butts. I never saw one with the standard tapered barrel. Are you sure it wasn't a nickeled M-36?
I'd suspect a re-barrelling job if you saw a round butt, but some may have been made that way. The gun pictured has target grips.
I had one about 1989, selling it to a neighbor when I needed money. I hated selling it. Thought it should be a routine catalog item. Those are superb small defense and trail guns. I have not seen any for sale in years. They are uncommon!
The later (full-lugged) M-60-4 is even better for field use. I love mine! Some of those have flash-chromed hammers and triggers and some have the usual color case-hardened ones. I think these date from around 1990-1994.
IF this gun checks out, it is probably worth the asking price, and you may have to pay that. But I feel that I should point out that until the M-60-4, the design wasn't officially RATED for Plus P use. (That info is from the factory, not from some random post on the Net.)
First thing, take your copy of The Book (or go BUY one) and see what it can tell you. Then, ask to examine the gun and see what it really is. The model number will be on the frame with the cylinder swung out. Even a nickled M-36 may be worth that price, but I'd hold out for stainless. (I wouldn't own a nickel gun. But many would.)
Let us know what you learn. If it really has the lighter, tapered barrel, that would be very unusual, as would the round butt. With rubber grips on it, are you even sure of the butt shape? BTW, I have Pachmayr Presentation Compacs on my M-60-4. It came with Uncle Mike's grips. The M-60-4 does have a round butt. But if you really have a tapered bbl. and a round butt, I'd suspect a M-36 in nickle.
T-Star
P.S. All of these guns have the normal hammer and the usual stainless polish. The DA-only NYPD guns are another item.