If that is your concern, then there is a very simple solution: you use 0.5 BTC to buy the Trezor, and then you buy another 0.5 BTC.
In 2013, I had bought 3 USB sticks for $10 ($3.33 a piece). I think that storing my coins in a USB drive is much better than spending $100 for Trezor.
If you're dat files are ever loaded on an online computer, they aren't safe anymore....