I have pulled up all the flooring on a property I am trying to move into. I am down to the 3/4 inch plywood sublfloor and discovered lots of dips, bows and some of the top of the plywood has began to peel. I was advised to pour a self leveling compound on top of plywood to level out dips and cover the peeling and before pouring the compound I need to sand down the high spots with floor sander. I have investigated purchasing the leveling compound and discovered it is expensive and not easy to do. would it be easier and less costly to purchase new 3/4 plywood and put on top of old plywood. or do i still need to use the self leveling compound. The total area I am fixing is 2500 sq ft.