I've gotten rid of cars due to crash damage (at the time 25 years old and 69,000 miles), vehicle needs changing (at the time 18 years old and 168,000 miles), engine throwing a rod (17 years old and 182,000 miles), engine flat out dying (24 years old and 200,775 miles), and most recently, engine giving out after overheating (8 years old and 261,000 miles).
Depreciation concerns would be a reason to BUY an eight year old Corolla, not sell one. You're fine.