Is it safe to purchase a Trezor wallet from someone else (that you might not trust)? Is there any way that something could go wrong if the wallet was tampered with somehow?
How much value does a day devoid of paranoia hold to you?
The fact you through in "might not trust" tells me you know the right answer.
If you want to save a few bucks just wait for another sale or mine on slush's pool for a bit.