First off I'd like to say thank you all for reading this, and thanks advance to anybody who answers.

I left the store the other day and my car would not start, On the dash it was saying start error. I have the truck towed to my mechanic's he tried to ground out system, change battery, change batteries in remote. His computer Was not telling him much for some reason but he did say it was not recognizing the key? After taking the battery out of the car and putting it in it would start then die and say start error.talked with the gentleman at Mercedes he said I should start with replacing key see if that works if not replace ring and DAS computer. All that is a lot of money to do and there is no guarantee that that's the problem he said. I found wreckers near my place that would sell me the whole system for $1300 out of a wrecked vehicle I was wondering if this is the way to go?

Thank you,
Sean