Deck and patio estimates are likely to have huge ranges because most of the cost is tied up in the materials. The difference in flagstone as compared to brick pavers, and the difference in treated lumber and composite materials can translate into a dramatic difference in deck and patio costs. The best idea with any project is to gather several estimates so that you know the range of budget that you need, but also so that you can figure out which contractor is giving you the best deal for your money.