What is the value of a Marlin 22 cal 882 ss micro grove barrel WMR?

It's really going to depend on condition. The .22 Mags have a lot of popularity in the south and Midwest, it appears, and I would have no trouble selling that gun in good (used) condition for $150.

Adding comment: Yeah, $150 to $200 is what they sell for here in the Atlanta, Georgia area. I bought mine (used) for $140 but it was missing the magazine. So I bought 3 extra mags for it, and a 4X scope, and rings, and a sling, and now I'm happy with this rifle and only spend about $200 on it.