It is certainly profitable for a type 1 civilization to move to a type 2 civilization as long as energy consumption and population continue to naturally grow as

It is certainly profitable for a type 1 civilization to move to a type 2 civilization as long as energy consumption and population continue to naturally grow as has happened so far here. Same thing for type 2 to 3. Also, I think that decisions about space travel are not purely for economic reasons and probably in almost any advanced species there is a large amount of the population willing to pay something to explore.