In 2003 I bought a 1993 Mercedes for 5% of its sticker price, inflation-corrected. 80K Km, new-looking. Everyone warned me about maintenance costs but the '93 was a rugged beast. Family road trips and multiple moving days and a lot of mileage. I was prepared for some expensive repairs due to money saved in purchase costs but got through another 10 years no problems, other than the 4matic AWD computer which just turned it into a solid RWD until I bought a used replacement.

Gaming the ripe time to pick a used model really depends upon design and manufacturing, but the sweet spot for reliable brands seems to be 5-10 years.