New to Madden: 2005 or 06?

[GaryM05]

I'm a long time football gamer, but up until now it's been all NCAA and 2K. So now that Madden is the only game in town and I'm needing my late summer console football fix, I'm wondering if it's worth it to shell out $50 for 06, or if I should just get 2005 for $10, as a lot of what I'm seeing in reviews and posts seem to indicate that the new game might not be worth the upgrade. If it matters, the things that are important to me are gameplay, AI, a realistic franchise, and having lots of flexibility to call audibles at the line (offense and defense.) Graphics, online play, and fancy 'extras' don't hold much value for me.

I know that $40 might not seem like much, but the wife and I just moved into a new house, and every dollar is precious. Thanks for the help!