[anonymous_1408732650]

Hi I recently pulled out of 2016 topps a 1991 Ryne Sandberg all-star #398 buy back. It's a double gold stamp operation desert shield 1/1. I have no idea on how to value this and consider sending it out for grading but has a full gum stain on the back. Any I ideas out there? Is it worth sending out with the gum stain? I will add pictures later