Need help pls, Coolant leaking near Diff skid plate???

Let me do a quick explaination from the start. I was driving around when my check gauge light came on and my temp was very high so I stopped by a gas station to buy coolant and fill with water. While filling up my radiator I noticed coolant leaking out but not from the radiator or the hoses and not the water pump. So I drove home and noticed that it leaked worse at idle but stops leaking after awhile with the vehicle turn off. So I checked everything again and looked under and notice it was leaking near the differential skid plate, but couldn't find exactly where. Does anyone have an idea where it could be leaking from and what I might be looking at fixing? It would be great if you can provide some rough estimates on how much the fix would be. If you need anymore information let me know. I appreciate all the help, thanks in advance, Joe

When my 99 Tahoe had a similar leak it turned out to be the intake gasket. The aluminum intake will eventually corrode (usually on the front corner) the corrosion allows water to get past the gasket. When mine occured it happened all of a sudden and much of the water looks as if was coming from under the engine. If you want to check for this problem just get a good light and shine it over the intake (near the front and above the heads). If your block still has water in it all you have to do is turn-on the engine and you'll see water squirt out of the area near the intake. It's kinda hard to see with all the hoses and wires in the way but if you look closely you'll see water squirting out with the engine running. If not then it must be something else. Gil in Tex

As said it may be the intake.
Any coolant in the oil?
But proper testing first.
Check all 4 corners of the intake gasket and also the heater hoses and pipes.
A pressure test is on of the best ways to find where it is leaking.
Pump up rad pressure and check cold and warm and the hot.

On the cost have a repair shop give you a estimate but you will need it checked out first to know what is leaking.