This discount pushes the price of their base model device under $80, which is impressive.
Sadly, the hardware is not open-source, but the firmware is and you get an air-gapped device. Sounds like good value to me, but I'd have to try it for myself.
That is a good price, but few bucks more for Pro version is absolutely worth it, battery is much better and rechargeable, there is fingerprint sensor, and it has Anti-Tamper Self-Destruct Mechanism.
I am not sure how good that anti-tamper mechanism is, but it's better to have it if you can, and Essential version doesn't have it at all.
Now they started with even bigger 40% discount, but you need to do some twitter activity and join their discord, maybe you can even write few words about Passport wallet
https://nitter.poast.org/KeystoneWallet/status/1593272854887378944#m