Somehow I do not understand the question. But I am not so bright anyway. I could ask should I buy a Mustang or a Tank? Neither is a substitute for the other. And one is definitely more expensive than the other. Lenses for an M; maintenance and ordnance for the tank. And whatever goes with aniPad.
Now, if you asked should I buy an equivalent to an iPad or an iPad, well, that would make sense but an M-body?
In other words as has been stated before, it is a matter of priority. Need priority is different than want priority. Only you can answer either priority question.
Or, just get an SP and forget about!😉
Good luck, it's always tough making decisions...