You aren't buying a phone when you buy the librem 5. You are funding the development of open source phones so there will eventually be a v2 and v3 which are better value for money when the hard work was done in v1.
You're funding a FOSS operating system and a phone with some security features. We already have dozens of open source mobile OS's, the hardware design is still proprietary. What's really needed is an open source baseband firmware and no one is funding that sadly.
Despite the baseband/cpu isolation I fear it still has a host of vulnerabilities up its sleeve. One AT command away from certain doom (yes that's sarcastic hyperbole with a sliver of truth)
Edit: It's the top one of the two linked by pengaru (https://news.ycombinator.com/item?id=25143382 / https://www.phoronix.com/scan.php?page=news_item&px=Zlatan-T...).
> Purism seemingly never tried to get better deal and the South San Francisco partner abused this so that is why Purism Librems are double the price they should be.