mig-31 vs Su-30 in operation and maintenance costs

this is from a conversation elsewhere with Commodore BJ in another thread.

we’re more interested in which is more financially economical in operations in the RuAF.. the MiG31 or the Su-30.

I argue that the MiG-31 is a larger, heavier machine with more complicated components (like its engines), is more fuel hungry, etc.

he argues its a simpler machine since it has a narrower tasks and should be cheaper to operate.

thoughts