I've just run a quick 1 million simulations of the finals using the following probability matrix, which is based on each team's current MARS Rating and assumes that there is no home ground advantage in the finals:

With this matrix and a slab of CPU seconds, I obtain the following probabilities for each team (1) playing in, and (2) winning the Grand Final:

Probabilities shown shaded green are those corresponding to value TAB Sportsbet wagers. Still we find that the TAB bookie is - according to MARS Ratings and my simulations - undervaluing the Dogs. He has them priced at $11 and I estimate them to be about $6.50 chances. That's quite a difference.

I'm also now suggesting that the TAB have the Cats inappropriately rated, so a wager on them at $2.50 represents (slender) value. I rate them value at $2.45 and above.

Finally, a quick look at the GF Quinellas:

Only the Collingwood v Dogs matchup continues to offer value. It's currently priced at $6; I'd be happy to take anything over $5.60.

(I note in passing that the only impossible GF pairings from amongst the eight finalists are Fremantle v Hawthorn and Sydney v Carlton, since these are the Week 1 finals matchups and one team from each of those pairings will be bowing out next weekend.)