A relatively low mileage recent model won't have much wrong with its
mechanicals - unless it's been in a crash, then all bets are off. But
the electronics cause owners' unhappiness. And nobody can look at one
car and know whether IT will or will not have problems. A fleet yes but
not a single sample.
In the USA M-B dealers (only) sell recent vintage cars with a Certified
Pre Owned warranty - 12 months to 100K miles. Such CPO cars are also
eligible for a purchased M-B Extended Limited Warranty at additional
cost - about $2,000 for one year and $2,500 for two years following the
Gamblers can buy used M-Bs quite cheap and take a chance on their repair
cost, others choose to stay within the system, pay extra and know the
inevitable repairs will be covered by M-B.
Repair cost apprehension isn't part of owning a luxury product, IMHO.