This is exactly what I have done too. Purchase the ad-supported version for (I think) 40 Euros less and simply never connect to the internet. That was over five years ago and I still don't regret it.

It has one more advantage: the firmware is really outdated. Normally I'd consider this a bad thing, but in case I ever want to root the device, the jail breaks are probably for one specific old version of the software, to which I'd have to upgrade. Not downgrade, if that's even possible.