Biggest thing I see is the price - 537,98 € ncluding 19% VAT., plus shipping
So you are paying well over Bitmain price if the math in my head is right. Have you bought from there? Just seems very very high on price.
http://asicminer-shop.de/Antminer-S5-GebrauchtgeraetI could sell a few used S5 from price 450 EUR piece + shipping from estonia.
I have a home 70TH/s different miners , and it is too much.
The price appears to be around 511 USD, they mention include 19 percent vat. This comes out to be around 413 if you take off vat paid upfront. Not not horrible price I guess if you do pay a vat.
But it is not an official reseller so you have no official warranty. I would keep this in mind with buying there.