Well it would keep Arca Noae running. 5.08 installed on my systems. By the way. but I am going to upgrade. Just having a non buggy way to install with a NVMe is worth a lot to me.
So we have pricing but my question is - is there anything earth shattering that would make me want to buy it, considering my practise of 'if it isn't broke, don't fix it'. 5.0.7 works on my computer and does everything I want so I am not considering upgrading unless there is something outstanding in the new version.
Whether you want to spend more for ArcaOS 5.1, depends exactly what you already have, and what 5.1 will do for you that 5.0.8 won't do. The main things are better DOS/WinOS2 support, and support for some (hopefully most) UEFI machines. You can also boot from GPT disks.
Some things will not work. Doodle Screen Saver can no longer use the DPMS support to turn off screens (apparently it is on the todo list, but not near the top). That is okay for screens that have a switch, but laptops don't turn the screen off (I, personally, see that as a minor regression).
NVME install is probably no different than what 5.0.8 does. I don't know of any problems with that, other than you may need to change he order of the drivers, to make the drive order what you want. I have no idea how the installer could read your mind, and do it the way that you want to do it. The installer does it in the way that most people would want it done.