It has never been a BETTER time to buy an aircraft, and never a WORSE time to sell one. Complete buyers market and lots of bang for the buck out there.
A Beech and MU-2 broker posted on an another forum a month or so ago - out of his last 16 sales/buys, the average paid price was 30% lower than asking. 30%!! And that's for an aircraft type and maker that has excellent pedigree and a reputation for quality. Try to sell something that's not a Beech and you're probably looking at even more discount. He also said the average sales time was about 6 months, but many not priced right could be on the market for up to 3 years. I can vouch for this because that's exactly what happened when I sold my Aerostar with fresh engines - you get taken to the cleaners.
In any case, this transposes overt to jets and TP's, too. You can get into good jets/TP's for not very much money these days. Just because it's an old $200K C501SP from the 70's, doesn't mean it's a trash truck, just that that market has collapsed, too. It will never come back for these older aircraft. So if that's what you want, then it's gotten a lot easier to get.