I still can't figure out why someone would pay $800+ for an S7 on eBay when you can get a brand new one from Bitmain for less. When I ordered mine, it took less than a week to arrive here in the U.S. No problems with customs, etc. Very smooth and easy. You could probably do pretty well buying a bunch from Bitmain and turning them around on eBay.
S7: $665 + shipping ($50) + tax (10-25%)
= USD 786.50 with 10% tax
= USD 893.75 with 25% tax
If it passes a boarder, the carrier (UPS/DPD,...) is charging again on top of that . So depending where you are living, USD 800+ can be a good deal. There isn't much difference in a used and a new S7 (its not a car

).