I would estimate the value in the area of 600-650.. The -2 would one of the latter revisions.. Not sure if there was a -3..
There were 4 variants of the 4516. The 4516 (1988-89) had some reported feed issues resulting in a redesign to the 4516-1 (1989-1992). Changes reportedly included frame / slide / barrel feed ramp / magazine changes. The 4516-1 was an improvement but reportedly did not cure all the issues.
The 4516-2 (1993-1997) changes included a redesign from a single recoil spring to a dual recoil spring and further magazine changes which reportedly resolved the feed issues. The final iteration sometimes referred to as the dash 3 (less common 1997-????) was a minor variant off the 4516-2 but as I recall, it no longer carried the 4516-n markings.
The 4516-2 or the dash 3 appear to be the most desirable. It is worth noting that some of the 4516 and 4516-1 were retrofitted with the dual spring using a bushing at the end of the slide to accommodate the smaller diameter guide rod.
The early magazines (yellow and orange followers) were typically marked for specific dash numbers only. In addition to the follower changes, there were potentially significant changes in the top metal lips. The final magazine with the black follower is supposed to be backwards compatible and were issued with later pistols such as the as 7rd 4513TSW (circa 2000) etc. There is a detailed discussion of mags on this forum.
https://smith-wessonforum.com/smith...-magazines.html?highlight=4516+mag+variations
Similar changes occurred on the 8rd 4506 mags. As far as magazine compatibility I would assume the later 8rd mags with black follower could be used in a 4516-2 but would stick out. Correct 4506 / 4516 mags are relatively scarce sell at a premium - think $50-60 or more.
I would guess $600 in good condition with 2 correct mags but no box or other docs. If you think the earlier 8rd 4506 mags with yellow and orange followers that stick out are a plus, add a bit. Personally I would save the earlier yellow and orange follower mags for range use or you can probably peddle the early 4506 mags in classifieds below.
In fairness, others here have reported the 4516, and 4516-1 mags with yellow and orange followers can be used interchangeably with the late 4516-2 mags with black followers.