It's from a good rope manufacturer and looks the real deal.
It's actually not that cheap, when I worked at Boating Hardware in WA we had 10mm double braid for about $2.60p/m which is not very mich more expensive than this ebay stuff and you can get the exact lengths you want.
So try you're local chandlery first, no wastage and you won't end up with all your sheets the same colour!!
I have bought from this seller a few times, but direct from his website ropegalore.com.au/ ask (Ray) to go on his mailing, he sends out a 10-20% discount code every so often, very fast replies & delivery, no affliation just a happy customer.