Offense
A .1/.2/.3/.4 four-year weighting system assigns Raul a .372 wOBA*. Knocking off 5% due to age (he'll be 37 next June) drops it to .354. Marcel's projected wOBA* is .349, so we're in the right area.
Defense
I'm going to be really nice to Raul and call him a -10. In reality, it could be as bad as -15 or even -20, but I'd like to give him the benefit of the doubt so that we can reasonably maximize his value.
Overall
If you run through the WAR formula, you come out with a final answer right around 1. If you call Raul a -20 defender instead of a -10, he's almost replacement level. If you go the opposite way and keep him as as -10 while bumping his offense up to, say, .365, you end up with about 1.7.
As a DH, he's between 1-2 wins.
Conclusion
On the free agent market, teams spend about $4.8m per one win. So Raul Ibanez, at his unlikely absolute very best, is about a $10m player in 2009. Meanwhile, Raul Ibanez the Marcel projection is more like a $5m player in 2009. He is then, of course, expected to continue declining in 2010 and 2011.
Is Ibanez better than Ramirez or Teixeira? Of course not. He's also five years older than Burrell and seven years older than Dunn, and hits for less power.
Still, teams love Ibanez's professionalism, and one general manager predicts he will receive a three-year deal for between $8 million and $12 million per season.
This isn't going to go well for someone.