On ebay I saw it sold for $329 +
Yes, go into the sold listing, click new. You'll see the sold numbers
Is this the 1st gen ipad air or 2nd gen?
Link?ETA: This is what I get: http://www.ebay.com/sch/i.html?_nkw=128gb+ipad+air+4g&_in_kw=1&_ex_kw=&_sacat=0&LH_Sold=1&_udlo=&_udhi=&LH_ItemCondition=3&_samilow=&_samihi=&_sadis=15&_stpos=33154-2432&_sargn=-1%26saslc%3D1&_salic=1&_sop=12&_dmd=1&_ipg=50&LH_Complete=1