Haha! This is really Interesting!!

They'd Mostly Spend it on their Labs, their sibling robots and paying their developers. If I had to really narrow things down, just like this robot, I think most of them would spend it on every book they could find, to fill their brains not to get bored. But Most Importantly, they'd spend it on some Solar Panels and Batteries for emergencies. Maybe some some towels to keep sand out of their Fans... :D

From the Horses Mouth ;)