Given the *non*-eBay prices, it looks like they're worth it, at least to me. Have to take into consideration what they are: branded rounds. Don't know the mintages, though didn't look hard enough at the time & haven't checked in a while. Here's something for an idea of a possible mintage range, info from last March.. http://silvershieldcollection.com/silver-bullet-silver-shield-complete-collection/
Got mine in today! My take: Skip the BU, and spend the extra $6 or whatever for the proof.. Which is way nicer, IMO. The BU is just too plain & sterile, in comparison. I've got a lousy camera, but there's a YouTube video out there on the proof. My 1st Silver Shield stuff.. Pretty decent quality for a branded generic. Would consider other proofs.
