If it’s in that good a shape and you like it it’s almost a no brainer to keep it. You’ve already taken the depreciation hit and you’re now just spreading the loss out over more time. After 10 years condition has more impact than age anyway. You might eventually reach the point where repairs get high enough you question the economics of keeping it. But you’ll have to throw a lot of money at repairs to equal the depreciation hit you’ll take on a new one.
I have a 16’ 1989 TT that was bought new and it’s in excellent condition so the current value – what I’ve been offered – not book value, exceeds a quarter of what I paid for it new. So you can see my depreciation cost spread out over 25 years has been peanuts. The frig went out a couple of years ago and cost almost $900 to replace and I didn’t flinch. That’s a fraction of the hit I’d take in depreciation if I replaced the TT because of it. Besides, the layout and construction is better than anything new we’ve seen for years. You could trade it if you’re just ready to spring for a new one, but from a fiscal standpoint it makes little sense to me.