"7 model years old/400 hours -
"7 model years old/400 hours - so about 60 hours a year average - not bad. You want your hours to be neither too high (possibly worn out) or too low (not run, rust sets in, usually not maintained if not used regularly).
In decent shape with maintenance records in a private sale I would expect to see them listed for 8 to 10K for the pair (freshwater run) up to 20% less if they have been running in salt.
Make sure they have solid compression numbers they are getting to the age where a rebuild could be in their future.
"New" a pair of 250's could well top 30K so you have to do the math and determine your own comfort level."