I am traveling in Europe with my unlocked phone. I bought a prepaid SIM with 1GB of data in Belgium. I didn't use more than a third of that, and I don't expect to be back in that country for at least two years.
Now I am in the Czech Republic. My phone alerts me that (as the SIM salesperson told me) data will work but at high data roaming costs.
Since the card is prepaid, is there any reason to not keep using it until it cuts off? (And when will that be? There's €10 of voice credit with the account.)