Tough one to value. It's a rather niche piece and likely not one that is often counterfeit, so you're probably safe on that front. There isn't a single one of these available anywhere in the U.S. All the ones on the market (ebay, chrono24) are from outside of the U.S. It seems that the one with the rubber straps are being offered for a higher price than the mesh bracelet ones. Regardless, you're looking at paying from $8k - $10k, so I'd probably try to get in at somewhere under that range.