They seem close, and in situations like that I go to the ESPN fantasy player rater which compares a player's stats to the league average.
The only drawback of it in my opinion is that it undervalues players who have been injured.
With that said, it rates Halladay at 9+ and Youk at 6+ even considering Halladay's DL stint.
I pretty much agree with that. Youk is lacking in HRs a bit. His biggest asset is that he will give you consistent runs and AVG and he doesn't get injured. The same could be said for Halladay in terms of consistency however.
Bottom line, take the deal (consider your roster though, I obviously didn't take a look at it)
I guess people usually post their question link too (I'm a bit new to this forum, sorry):viewtopic.php?t=392817