Default is it safe to buy nexus from hong kong ?

hi

time has come when need to buy new tablet and think about nexus 7 4G

but not available on amazon ( uk amazon won't send the item to ireland ) so went on ebay and there is few offers from US & hong kong,

wonder how safe is to buy from Hong Kong? want to avoid fakes !

any way to see if the nexus is genuine ?
with serial number ?

please advise