How ,much should a Valve cover gasket Set Cost to be installed?

What is your question?

I went back to Tires plus where they had done my brakes and 2 new tires, and just this month a oil change and new alternator belt for 107.00. I was told I needed a new Valve cover gasket replacement and a new tire that I had not replaced yet, as well as a new battery and a O ring Camshaft sensor. The estimate was 749.00 I feel like that was way to high, So I called a local shop here and they wanted 325.00 to replace the Valve cover gaskets,Tires Plus was 423.76 which was the highest price I was quoted.