What a stupid method, why would people buy the vouchers on eBay? Only complete retards would do so, and I doubt that many of them exist.
Umm.. yeah it may be stupid but people are buying them all day for easily double the price they are on Cex.io. I don't get why someone would either but there's tons of people that I guess don't know how to get Bitcoins elsewhere buying them up. Check the completed listings before you just assume no one would buy these when you really have no idea -
http://www.ebay.com/sch/i.html?_sacat=0&_from=R40&_nkw=cex.io+vouchers&LH_Complete=1&rt=ncTons of people making a living on selling these vouchers on ebay or sites like fiver etc.
And I'm sure your aware the chargebacks on bitcoin related sales are rife on Ebay?