While this is not possible now, in the future Blizzard is actually going to allow it. In their official Auction House FAQ, they state:
What items can be traded in Diablo III?
Nearly everything that drops on the ground, including gold, can be traded with other players directly or through the auction house system. Aside from certain quest items, there will be very few (if any) items that will be “soulbound” to your character and therefore untradable. We are also planning to allow players to buy and sell characters in the auction house at some point in the future and will have more details to share on that at a later date.
Source: Auction House FAQ
This is not possible yet, and they can always change their mind, but once they prove that the RMAH works, I would bet they go through with this. I'm sure they'll be happy to let you buy and sell characters at whatever prices you wish, and humbly charge a barely-noticeable percentage fee for helping you out.