There are a few minor upgrades/updates on the 2003 vs the 2004, the most singificant is the hydraulic clutch.
I've got a ton of upgrades on mine with 14,000 miles and perfectly mint - new tires, etc, and I started listing it around $19,900 last May. I went down every other week to $17,500 and never got a call though August. It's been sitting covered since May, and it's gonna stay sitting for that. For the kind of stupid money people are selling these things for, I'll just stick mine behind the bar.
It's crazy when you see $25,000 bikes selling for the same amount of money as a run of the mill Deuce that sold for $10,000 less.
I don't get it, but if you're a buyer, now might be a perfect time to shop. If the economy turns around, the SED values have to start rebounding at some point.