We have many more pressing needs such as signing a striker, a holding midfielder, a replacement for Sagna, a replacement for Fabianski before forking out 20-30m for a better version of Gervinho.
Currently we have Walcott, Chamberlain, Podolski, Cazorla vying for the wide-spots and that's before the likes of Wilshere who's unlikely to get as much game time in central positions as he'd like and a genuine talent in Gnabry. I don't see how anyone can justify spending money on this guy.