Radiator leak 01 Venture... need help

I have a 2001 Venture with a radiator leak. The van has 48k on it. I believe that the radiator is some type of composite plastic.
Has anybody had one of these repaired before. I am very disappointed that the radiator would develop a leak with only 48k miles on it. I have been getting labor prices (200-250) and repair prices (75) and replacement costs of up to 400 and up. I am also in the process of contacting GM to see if they can help me.

Please provide feedback.

Thanks, Vince

We recently had the radiator replaced under warranty on our 01 Olds Silo at 55K miles. It had a small leak that was not easily visible but they found it when replacing the leaking AC condensor. My only indication was a dropping fluid level in the coolant overflow tank that was also partially caused by the leaking intake manifold gaskets.

The new radiator is composed of composite plastic on the two sides (where everything connects) and aluminum for the heat exchanger.

I hope it lasts longer than the first one!