Honesty. Building decks isn’t rocket science, but it’s also something that is worthwhile investment. Hiring a deck pro will produce a better quality deck every time. That said, it’s important to find a deck professional who will be open and honest with you about the time involved and at least some general breakdown of costs.
For more information, see this article:
http://www.illinado.com/should-i-hire-a-deck-building-pro-3/