the dangers as i see em are:
1) inevitable VAT and courier handeling charges, so add 20% and a tenner, goods sent from china and the far east via post will often slip under the customs and exercise net with basic descriptions of 'electronics' and a nominal dollar valuation however established international couriers dhl etc are allways above board with descriptions and valuations as they also charge you a handeling fee for taking your vat payment for the taxman to 'facilitate a speedier delivery'
2)Quality and getting the goods described... the alibabba site should offer protection here, tho it may take some weeks to resolve and get a refund at a different exchange rate
But dont get suckered into any off site contracts, as when doll house sized kegs arrive you wont have any comeback at all.
its a punt but worth it imho, if i didnt have a full stable of kegs i too would be tempted..