AC problem

My AC was working fine,I turned it off for about 30 mins and now the compressor won't come on.I had a RV repair guy out and he went on the roof and said it was making a clicking sound that he has never heard before,He wants to replace it( Duo-Therm) with a Coleman for 1300.00 Does that sound like a fair price? We can't put it in the shop,it will have to be done onsite.