It's true the going rate for a loaded up (46-48K msrp) '04 SSr is around 30k. I've been haggeling with a few local dealers for the past month, and paying attention to the market pretty closely. Regarding your deal, I believe at the time you purchased it was probably a fair deal, but inventory build up over the winter slow sales months caused this. They just made too many '04 my units. I'm actually in a quandry as to if I should pull the trigger now, or wait until the '05's drop (still an unknown). Last check on gmbuypower there are over 100 '04's on the floor within 100 miles of me (Detroit). Of course I bought one of those 1 in 1000 ($100) raffle tix mentioned on another thread - that happens this weekend so I'm not doin anyting until after that.
Regarding depreciation, most lease companies are holding the 3 year residual value of the ssr at around 18k. (I'm not leasing, but it is a realistic number of what the vehicle will be worth).
I know everyone here is hoping the price erosion stops - Lansing Craft Center is shut down and only plans on building 40 per day when the restart. This should help, but as others here have mentioned, the market is real soft for this type of vehicle. GM is struggling even selling their regular trucks and stuff.