First off, it's not a "depressed market" for every aircraft type. If you want a new G550 or G650, you'll pay the list price, and wait until 2013 for the G550 and 2015 to sit in your G650. Most modern aircraft are moving well as long as the owner understands that the values of four-six years ago were an anomaly.
The credit history of the principal will determine alot of the variance in pricing quotes, as will the history of the flight department.
That said, expect to pay from 1.2%-1.6% of the value per month, plus hourly reserves and insurance.
Opinions vary, this is mine!
FR