Perma-Columns are 10,000-psi precast reinforced concrete posts with ribbed plastic-and-fiberglass pads at one end and galvanized post bases at the other. You install them with 3 to 4 inches of concrete exposed above grade to keep wood posts away from ground moisture. Prices are $46 for a 4×4 40-inch column, $71 for a 6×6 40-inch column, and $80 for a 6×6 60-inch column.
Perma Column, 888/699-8875, permacolumneast.com.