First bike help!

I'm not a new rider, but I'm looking to make my first bike "purchase." I took the MSF basic class before 12th grade in 2002. The only bike I've ridden prior to that course was my dad's used C-something125 (slow). The 250's in the class were fun.

So, to kind of celebrate, I went to Ducati Seattle a few months later on Thanksgiving weekend. I've gotten to like the Monsters so I asked if I could test ride the new (back then) 2002 Monster 620 Dark. The sales dude heard my story so he said, "Before you go, take a spin around this garage so I can see how you handle going from a 125 to a 620 bike..." I was like, ok! A few laps later, "Hey, look good! Enjoy the test ride!"

I come back in love! OMG.

That was over 6 years ago... man time flies. I love the lower Monsters (600-800). So now, I want to finally have some fun while I'm young, and get my Ducati!

Should I go for new or used? Do they depreciate fast? I found some ppls ads for "well-maintained" '01 Monster for $3300. Is this a good deal? At the same time, my friend said (just to compare) he saw a '05 RC51 <2500 miles for ~$3000.

How can I find the best deal for a Monster? Thanks!!