Last '04 ST4s I saw for sale was a gorgeous example with all three Ducati luggage cases and high windscreen. Had 1,500 miles, in the Reno, NV area for $10500. Grey over red wheels (the Senna-knockoff scheme). That was over a month ago (so a little early for prime selling/riding season).
If I could have gotten financing, I'd have bought that one in a heartbeat. Unfortunately, my SS is only worth around 6500, and I just can't come up with that extra $4k right now. :-\ It's a shame, because long-distance and some 2-up is the kind of riding I want to do.
So yeah, $9500-$10k is probably spot-on if you've only got the sidebags. If you have all three factory cases and any other goodies, $10500-$11k would be fair.
Got any pics?
EDIT: looks like the poor bloke in Nevada is still tryin' to sell his... (
http://reno.craigslist.org/mcy/622392505.html) I hope it moves soon, because I really don't need to be tempted to make stupid financial decisions right now; I need to buy a house next year.