I definitely wouldn't connect any USB device I don't know the provenance of to a computer that is used with BTC or my personal data. Feel free to call me paranoid but I don't even use USB cables if I don't trust the supply chain because they can be compromised. (Soon, you'll be able to buy a compromised USB cable for like $50: https://shop.hak5.org/products/o-mg-cable )
Ultimately, it's up to the buyer. If you think the risk is worth the possibility of saving a few bucks, go right ahead.
I purchased a three pack directly from trezor