Why not just buy from the site itself or amazon? You could get a compromised one from buying it elsewhere and in the end get your bitcoins stolen (especially if you are a newbie at using one of the hardware wallets). Also, consider just buying other hardware wallets as I believe Trezor wallets has been previously hacked due to the chip they are using (google it, don't trust my word for it). Personally, I have a ledger wallet which is I think is a quite nice also I've seen a lot of reviews about it comparing it with a trezor and most of them prefer the ledger over the trezor.