How to auction shared item with a roommate?
If you think that the distribution of your value and your roommate's value are the same then I would suggest that you consider the following bidding protocol:


each bidder submits a sealed bid, $b_i$.
the highest bidder, $i$, received the console and makes a payment of $\frac{b_i+b_j}{2}$ to the loser, where $b_j$ is the loser's bid.


Cramton, Gibbons, and Klemperer (Econometrica, 1987; Section 4) show that this is an efficient way to dissolve a partnership with joint ownership stakes in an asset.

If you think that the two of you have differing value distributions (e.g. because your roommate has a new friend) then Cramton et al. show in Theorem 2 how to adjust the pricing rule to restore efficiency. 

I highly recommend taking a look at the Cramton et al. paper. It's surprisingly readable for an Econometrica.

Let us know how you get on if you decide to try it out!