FOSSOS looking at the protectli its not cheap. The VP4670 with the same CPU, 32 GB and 1 TB SSD is 876,00 €
You are looking at an outdated model with the according price tag from that time. A VP6630 should be able to outperform the older i7. TLSense doesn't even have anything in its portfolio that is comparable - their newest i-Series chip is this 5 year old i7.
For building it yourself:
- Ryzen 5500, stock cooler should be plenty for such applications as a firewall.
- AM4 mainboard - preferably with an A520 chipset from Asus.
- 16-32GB of RAM should be more than plenty
- Case and PSU should be up to you. Anything will suffice - I usually recommend bequiet for the PSU if you want it to be reliable for years to come.
- NIC is the only hard part really. Intel X550-T2 should work, but you will need to do some research too for 2.5GBase-T auto-negotiation. 10GBase-T seems to work flawlessly though from my quick research.
- SSD - take whatever you want. It's not really critical in a firewall. Cheap one for 20€ should suffice.
With my German pricing, I'm at around 420€ plus shipping for the parts (although with shipping it should still be under 450€). Throw in some nice case fans and you have a very flexible system that you can tweak and fine tune to your liking. At least compared to all the other offerings from these AliExpress boxes.