By Samanda Dorger Some used cars are selling for more than their new counterparts. Here’s how much money you’ll save – or lose – buying a used Tesla, Mustang or Mercedes. Back in the old days —say, 2019—buying a used car could save you a lot of money. The conventional wisdom was that new cars lost thousands in value as soon as they’re driven off the lot, saving used car buyers as much as 20% to 30% in the first year. But with pandemic-related semiconductor chip shortages leading to low inventory of vehicles and resulting higher prices, things have changed in weird, and expensive, ways. The ave…