Heck, didn't Barrichello had as much money as Senna, or close? Bring him back. I'd rather see him back for one year, than Bottas, seriously, especially if we lose Maldo.
The last time I heard, barrichello was able to convince a couple of more sponsors totaling to about (I think) 4-6 million.
If and that is a big if barrichello does come back to williams, there is a big possibility of bottas getting pissed off and resulting in him leaving to a rival team, which I am sure no williams fan (such as myself) would want. I and I'm sure most people here see bottas having more potential than (dare I say) hulkenberg. And barrichello, while I respect the guy a ton, he had his chances, won races and whatnot pretty much everything in f1 bar the WDC, but he has passed his prime and I see no reason for him to return to f1 with us.