cwlongshot,
At best ,Ruger Model 77 caliber value added considerations may have once been a footnote in the gun blue books. But with Ruger introducing the limited runs and now the caliber in a new rifle again, you may expect no additional value over the previously standard calibers. I did sell an older version like yours (a .30-06) several years ago to a fellow who was convinced the tang safety models are better than the current rifles. He made a generous offer. I did this carrying the rifle around at a local gun show.