As much as I prefer Matri to Quagliarella, I see two reasons for selling Matri:
1. He is worth more; and
2. Quagliarella has this confidence (arrogance) that seems to enable him to play at quite close to his best even when he has been out of favour. Matri doesn't seem to have that ability and needs more games and more things to go his way to gain the confidence to perform well
I'd still be selling both of them if the opportunity presents itself.