Some Nikon 35mm bodies even cost as much to buy second hand as what they were selling for when they were new several years before. I only refer to dealers here in the UK, but the last new price for the FM2n back in 2001 was about £400 for a chrome body, and around £20 more for the black finish. Today, mint condition examples of these bodies fetch virtually the same price. The same goes for the FM3a. They still command a high price even though they were discontinued in 2006.
Nikon's manual 'ai' and 'ais' lenses tell the same story.