BMW Repair: BMW 528i 98 Coolant Leak, chapman bmw, coolant leak

Question
The car has 88 000 miles and runs great. We bought it from a dealer in Scottsdale Arizona, 3 years ago with a 2 year  extended warranty and since have performed all repairs there. Probably because of the heat, we have replaced almost all hoses, water pump, radiator and when I thought that was all, yesterday I noticed 3, 4 tiny drops of coolant. Took it to Chapman BMW and the diagnose was possible wear at head gasket. The car has not been overheated. Dealer estimates parts and labor to $2,300. Is it possible water to leak outside from the gasket; is this a usual wear for this car at this mileage; is the price quoted reasonable; is it not better to just trade it than doing this repair, does the repair guarantee future problem free usage?  

Answer
Ivo, Ask them to show you where the leak is. It is possible for coolant to leak from the gasket. $2,300 is a little high. They should charge around 16 hours labor plus parts. It is also a good idea to have the cylinder head sent out and pressure checked for leaks and examined for cracks. Head gasket blown at 88k are uncommon. One repair does not absolve the car from future repairs. The trade in is up to you. You can always get a second opinion and I would recommend before such an expensive repair just to make sure.
-Evan