I recently bought a 2009 2305 with 850 hours on it but not a lot had been done to it other than oil and filter changes as well as an occasional greasing of the loader (by me). I bought it from my next door neighbor that bought it new but is moving back to the city where he lived the first 60 years of his 70 years. He used it mostly with the FEL and to ride it to and from his mailbox that is about 1,000' from his house. The 62" mowing deck has been sitting in my outbuilding for the last 6 or 7 years and has had little use. The 4' bush hog and the rear blade might have been used two or three days total since they were new.
I changed the antifreeze for the first time and what came out looked almost exactly like what I put back in. I changed the hydraulic fluid and filter and it looked pretty normal to me. The screen had a little debris on the bottom and the magnets had about the same amount of filings on them as you see on magnetic oil plugs when you change the oil. When I changed the differential oil, the old grease was black like you normally fine in an automotive differential but nothing out of the ordinary. I also changed the oil and filter in the engine. He replaced the battery for the first time 2 or 3 years ago.
I don't think the delay in changing the fluids has done much harm as it runs fine with no signs of abnormal wear and tear (other than the yellow seat won't come clean) or any other signs of misuse.