Quoted from PinMonk:I think the difference is the GZ is not sold by Amazon. The stern store ones are sold by amazon, so probably would qualify, but they drop out of stock pretty quickly.
This is correct - I've purchased a pin directly from Stern (listed at MSRP, not an inflated price like from that billiards place) using their Amazon storefront and received about $450 worth of Amazon points. You will pay tax, of course, but the free shipping is nice.