How much would it cost to throw a cell in PS4?

[raygun]

Maybe Orbis WILL have BC...

"However, there's a fair amount of "secret sauce" in Orbis and we can disclose details on one of the more interesting additions. Paired up with the eight AMD cores, we find a bespoke GPU-like "Compute" module, designed to ease the burden on certain operations - physics calculations are a good example of traditional CPU work that are often hived off to GPU cores. We're assured that this is bespoke hardware that is not a part of the main graphics pipeline but we remain rather mystified by its standalone inclusion, bearing in mind Compute functions could be run off the main graphics cores and that devs could have the option to utilise that power for additional graphical grunt, if they so chose."
(http://www.examiner.com/article/xbox-720-and-ps4-graphical-capabilities-discussed-detail)

What's this extra rumored chip for? It could be a cell, since in the early design phase of the PS3 they were not going to have a gpu, instead using the cell as the gpu. We can only hope, I also want BC, I don't want 2 consoles and will delay buying a PS4 if it doesn't play PS3 games. If it is BC, I will buy a PS4 day one.