No, that's quite reasonable, but I'd like to see the small print and the baseline you'd have to add-on to.

Here in Spain the lowest rate you can get is a data only sim for 29€ limited to 5GB (after that the speed is reduced to 128Kbps).
The same company also offers a voice+data sim, but with that you'll pay 5.8€ up to 500Mb, then it's 10cents for each megabyte.
You can get apparently lower rates from other companies, but they're very limited (like, 100MB or so).
And none of the above works if you travel abroad (it'll actually works if you're willing to pay your entire wage in roaming charges).