Me too. I don't think he's that motivated by money. Look at where he's spent the cash at villa - the pub, the moasaic, the training ground, forfeiting sponsorship money. They're all things that build the heritage/class of the club rather than instant success or line his pocket.
See also the Lerner wing at the national gallery.
Furthermore he already has more money than he can spend so £20-£50m probably wouldn't make that much difference to his lifestyle.