Seems pretty expensive for Ursa Luna ... think that's 19.6Y each? So for Ursa Luna then, you probably can't even buy a single merc ... don't think you get enough money on that level.
how did this happen? it almost looks like an integer underflow (go negative on an unsigned integer, resulting in either an error, or a very large number)
I googled it to see if it was some power of 2 to check if it maybe was an overflow. Or if it had some other nice mathematical properties. In all honesty, I was just bored..