Leasing contract now expires (after 3 years): How to proceed (loss of value) ?

Hello guys, maybe an owner from the Auris early days can tell me something about the loss of value of a three-year-old Auris today ! My “case”: My Auris Sol 1.6 petroler (124 hp) is leased, the lease with km-reckoning expires in December after exactly 36 months. So now the question arises, how I continue to drive afterwards. For information: I can not keep the registered 45000 km, probably come to 50000 km and would have to pay about 550 €uros multi-kilometer penalty. Otherwise age above average condition, I say…, because I clean a lot 😉 , in the meantime at my expense newly matured with all-year tyres. If I bought it for the due final rate, the amount of which I don’t want to mention here (after all, you should speculate what I would achieve if it belonged to me and I offered it on the free market or gave it to another dealer in payment), TÜV + inspection would be due for 350 €uros. so far the brake pads were changed because of the annoying brake squeaking, moreover rusty wheel bolts were replaced. So what would be the estimated value loss after 3 years and after 4.5 years (if I decide to continue one and a half years) ? Would I be happy about answers !