When do you sell your boat?

I was talking to someone the other day about my 2004 wakesetter with 690hrs. and he asked when i was going to buy a new one. I've always been an "out with the old, in with the new" kinda guy, but with my boat its a different story. Granted an '04 is getting up there, but i have countless hours fabricating speaker boxes, amp racks, led lighting or just sitting in the boat thinking of little mods to make it "better" or "nicer". My question is when do you sell your boat? Do you have any mods to your boat that make it "yours" and does it make it harder to let go of if you did them yourself?