If he takes paypal any buyer is protected it is a small buy it should be safe.
Just don't pay him with anything but paypal.
If he does right by the 4 paypal buyers it would be a start.
I am USA based I do not want to do escrow for this.
I do own one of these and I can tell you these are not set it and forget it. They like cool air need room to breath and are loud.
read this thread to be sure you want one of these as they are harder to do then s-3's
https://bitcointalk.org/index.php?topic=795477.0mine is running here. I am using an older version of minera so take the 89gh and x 16 = 1424 on an underclock to freq 230 vs 240 . but to keep unit cool I keep my garage door open.
temp is 88f or 31c next to the miner. I use a rasp pi to run it. my outside temp is 44 f or 7 c without the door open gear warms up a lot.