What do you mean by a turbo doesn't help with power anymore?
The turbo gives about 50% more power but only after the engine gets up to 2000RPM. The 300SD has slow acceleration until the engine gets revved up and there is very little torque boost from the torque converter. The 300SDL 6 cylinder has a much different torque converter that gives better acceleration.
As far as the reliability of the turbo, I see very little said about them here on this web site. If there was any big problem with them, I am sure there would be more complaints about them.
I can't understand why people discriminate between what they pay for a car and repair costs. They don't complain how much the purchase price is, but let there be a repair bill and this is terrible. Together they are both the total cost of owning the car and come out of the same pocket.
It might be because most people buy more car than they can afford. If you can afford $10,000 for a car, you should probably buy one for about $7000 and keep the other $3000 for repairs. That way you don't pay more that the $10,000 you could afford in the first place.
As far as Ebay is concerned, I bought 2 cars (1 cheapie and 1 good one) using Ebay and I was very pleased with both.

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