Yes, it is only because of the disk limitation, my primary disk is 1TB nvme still I use my system for other things so I can't go for a full node with my current system unless I increase the primary disk. And a secondary disk is only possible through SATA ports and external disks, but I guess they're not suitable for the job so going with the pruned one now and maybe try to get a cheaper dedicated device to run 24/7.
Ok, so I suggest you keep the minimum amount of memory, there is no reason for anything larger. Also, take into consideration LoyceV's suggestion. A testnet Core instance will give you all the features of a mainnet instance, but with the additional feature that you won't be able to screw anything up and you will also be able to test literally everything, without having to spend money to do your tests.