To be fair, Capcom DID somehow lose the source code. This wouldn't be the first time that they would do this sort of shenanigans (case in point: much of the promised content for the MMX collection being absent, due to Mega Man Maverick Hunter X's development).
But still, indulge and enjoy!
It's great that the new generation will get acquainted with the Mega Man Hunters, rather.
That part was hilarious!
Agreed. Though, I was slightly accidently spoiled by the mention of the castle being quite tall, it didn't keep me from getting a load out of that moment.
Again, where does he get the money for these places?
Depends on the circumstances, really. It can be the result of amassing funds (in low profile, of course), recycling junk, or having technological "supplying" (e.g. Wily's teaming up with Dr. Light, in MM3).
For instance, if the Wiki info for Crystal Man's any indication, he most likely made money for building the MM5 castles, from selling his counterfeit crystals.
Though, in the case of MM10's, you could say that he's had left-over funds from his bank account, or just took advantage of the Roboenza frenzy, to take all the time in the world to build it and not get noticed.