Cost for Septic System and Well

everything is a money racket these days. in my area I had to go down 285 feet for "good water" whatever thT IS MY OLD WELL WAS 120 FEET BUT THE ATER WAS CORROSIVE. THAT WELL "COLLAPSED" ALOT OF SANDSTONE. 20 GRAND FOR A NEW WELL AND CASING AND THEY SAID THEY SOULDNT GAURN==ANTEE TAHT WELL WOULDNT X=COLLAPSE EITHER BECASUE OF TEH SAND STONE...