Not sure if it needs head gasket repair or not. I had the water pump replaced a few weeks ago by Purcell's Tire. They told me there was no water in the oil, but the oil cap had a bit of milky color to it...they said it wasn't the head gasket. It is now again running high temp almost immediately after starting. I checked the oil, water & coolant, they were low, so added those. This is w/the AC running...I live in Tucson, AZ and it is over 100degrees.

Could be a few hundred, they're not too difficult to do. A mechanic should check the oil and coolant, if the oil id a coffee color, then there was cross contamination, and the engine may be damaged for good. If you catch the gasket leak early, you can repair it and continue driving the car.

$1,300 to $1,800 depending on where you live...

It could just be a stuck thermostat. Cheap and easy to replace. Have the cooling system pressure tested to see if there is any internal leakage before spending money on engine repairs that might not be needed. And BTW, tire shops generally are not a good place to take your car for mechanical repairs.

more than the car is worth

Repair a head-gasket? There is no such thing. The cylinder heads must be resurfaced flat, then the head-gaskets must must be replaced. A Ford Garage charged $1,200 ten years ago.