How Much I've Spent on NX

However once I start doing ultimates I guess I wouldn't even go near to where the monsters died so the pet wouldn't really help...

If you're at newties, maybe.

If you're doing ultimates at skeles you'll be circle two levels of a map, nonstop while someone else does the same to the other two, generally.

All that aside, either map means being constantly hit, which means having mguard on, which means having to keep your MP high enough to keep you alive in the event of a direct hit, while blowing 7k per pop. Pets and autopot are pretty helpful there.