As I've read, the last combo offer with cash was Frink + Homer Buddha + $50,000 for 250 donuts. If you paid full price for Frink and the Buddha, the $50K cost you 85 donuts.
Which terrifies me, cause I'm ready to buy the Brewery and a discount of the Sign would be worth the wait. But I won't spend one donut on ingame cash, so if the deal costs more than the 360 I'd spend to buy them both then I won't touch it and I'd buy the Brewery tonight.
God I wish I knew that price lol... my next donut item is waiting on the answer lol.
EDIT: I caved lol. Buying the truckload now, used the money I was about to build a questline building with to buy a new plot of land, and added Frink and Duffman to my town (already bought Otto, and won SVT in a Buddha). No regrets. :)