Samsung officially releases unlocked Galaxy S7 and S7 edge in the US
The Galaxy S7 and Galaxy S7 edge can also be found on Amazon, Best Buy, Sam's Club and Target. The phones will work on AT&T, Verizon, T-Mobile, Sprint and US Cellular.
The RRP is $670 for the S7 and $770 for the S7 edge, but you can get a better deal if you shop around. The eBay deal is probably the best yet, the S7s are priced $500 and $590 respectively, but you can try other sites too.