I have an 04 model and having to make the same decision.  I am able to do all of my repairs and have been keeping up on repairs.  Before fall, I swapped out the single-speed hydro motor for a 2-speed.  Last year, a rebuilt hydro pump and hub was installed.  I went thru brake assemblies and installed new shafts and seals.  A few years ago, a reman 3-speed rotor gearbox was installed, as well as a used Mud Hog rear axle.  Trading combines to a newer model would require different bean head and corn head feeder adapter for the larger feeder opening.  If I keep this 2388, I need to pull feederhouse and rotor to replace the rotor cage.  I should replace PTO clutches and replace the feeder chain.