This would depend on several factors, type, size and condition of the pool and concrete surroundings. A qualified contractor is a must!! You don't want to end up with a swamp where the pool resided. Remember the pool held water. Access to the area is also a concern. In general most fill dirt and top soil is sold by the cubic yard (L x W x H / 27) You can get a rough estimate on material by calculating total volume (area needed to be filled) and checking for fill and top soil prices. The labor portion is the variable and depending on the contractor the price differences can be wide. USE A QUALIFIED CONTRACTOR check references, previous jobs performed.