You are taking a HUGE risk by selling on eBay right now.

Right now is the best time to sell miners and probably has the highest rate of being scammed.

Since price of BTC is rising there is a lot of demand, but if the difficulty keeps rising, your buyer has 45 days to send back your S5 and get a FULL REFUND including the shipping both ways.

Since you actually posted these miners on eBay you don't seem like a scammer but you really are better off just selling on here with ESCROW.