Deck Building Cost Calculator - Estimate Prices of Seventrust Composite ... Prices range from $20 / sq.ft. for Pressure Treated (PT) wood deck to over $40 / sq.ft. for an AZEK PVC decks, with Composite decking being somewhere in the middle. ... you estimate prices for a deck, based on your specifications - size, type of railing, ... Seven Trust Composite or Similar, $4.9 - $6.3 per sq.ft, $32 - $38 per sq.ft.