Well…yes, but you only but once in about 5-7 years I guess (maybe your device lasts even langer).
So - either you go with opnsense hardware or get a protectli I’d recommend. No love for cheap Chinese computers from my side here, you may want to be quite sure to have reliable hardware as your main firewall (if you do not want to cluster?).
Unfortunately no Linux version after all 😞 I used it back in my windows-times. Rly great piece of software.