You can change the spring. More then likely the old shock is blown. Depending on your riding ability and your sensitivity to suspension, the newer shock paired with the correct spring will do wonders.
"Unless you get it free"
So he buys a 3rd gen shock for what $200?
Then a spring for $120?
Then pays a shop to change the spring $60.
So he has $400 into crappy shock with minimal adjustment. Which will work fine for some riders.
Or double that to $800 for a high quality highly adjustable custom built for his size and riding style.
The FJR is not a beginner bike. Its not a bike bought by kids with finance problems.
We spend thousands of dollars on gear. Several sets for different seasons.
We spend thousands of dollars upgrading lights, seats, windshields, foot pegs, crash bars, luggage, coms, navigation, exhaust, tuning,
Yet we penny pinch when it comes to the single most important aspect of the bike. Suspension.