Why is the GSM shield so expensive? I've been doing some Googling for GSM shields and their prices and frankly I don't understand why they are so expensive on average.

The official one sold by Arduino is 71 euros for me (I live in Europe), and third party ones have similar prices.

A cheap dumb-phone is usually 30 euros and those phones have become really impressive these days, they have even a camera. When they are locked with the carrier the price can go as low as 20 euros. How is it even possible that a single part of what is supposed to make up a phone is more expensive than the phone itself? :(

Thanks in advance!
If you are ready to wait a month for delivery and also giving up flexibility by restricting yourself to just sending and receiving SMS, then you can go as low as €2 for a DIY kit on AliExpress.

By adding more money, you also get more features. Just sarch for "gsm arduino" or "SIM800", "SIM900".