I'm not seeing any drop off in buyer demand for very good condition John Deere 40 Series tractors from the late 1970's and early 1980's with lower hours, even despite the current struggles with the ag economy.
Latest proof came on a pair of southern Minnesota farm auctions today (July 28, 2018). The 1978 John Deere 4040 pictured below, with 4,671 hours, Power Shift, sold for $30,000 today on a farm auction in Mankato, MN by the great team at Maring Auction Co. (http://www.maringauction.com):
$30K is the 2nd highest auction sale price on a John Deere 4040 tractor in over 4 years. Here's a look at the all time highest auction sale prices on John Deere 4040 tractors:
Highest Auction Prices on John Deere 4040 Tractors
* Data by http://www.MachineryPete.com
I recall the record price 4040 well, sold on an amazing collector auction by Polk Auction Company (http://www.polkauction.com) in southwest Iowa. Here's a pic of that $46,000 rare restored 1982 4WD open station, Power Shift 4040:
Down the road in the small farming town of Welcome, MN today, the 1979 John Deere 4440 tractor, Quad Range, with only 3,559 hours sold for $32,250 on a sale by the good folks at Auctioneer Alley (http://www.landservicesunlimited.com). Here's a picture of this beauty:
$30K is sort of the magic mark for what nice condition 4440's sell for. Here's a look at the John Deere 4440's sold for $30K or more at auction going back to the start of 2017:
Recent John Deere 4440 Tractors Sold $30K or More at Auction
* Data by http://www.MachineryPete.com