How much does this cost to the nearest dollar?

Aqua-Pure AP124 Whole House Filter Replacement Cartridge
The 3M Aqua-Pure AP124 water filter is for use with many 3M Aqua-Pure whole house water filtration systems that use 9 3/4 inch by 2 1/2 inch water filters. The 3M Aqua-Pure AP124 filter is compatible with several brands of water filtration systems, including Filterite, Ametek, Pollenex, Sears, and Water Pik. 50 Micron level 8 gpm flow rate Filters dirt, sediment, and rust 50 Micron level 8 gpm flow rate Filters dirt, sediment, and rust Fits Housings AP11T, AP11S, AP12T, AP12S, SST1, SST2,

Price is $21.00

Price: $20.61