Although you are probably going to save more with a deck builder, they can still be better for certain major projects just because they have so much experience. Also, they may get better deals, simply because working on a number of decks in a short period of time will save money. If you are a DIY person, then you can usually do the majority of these projects yourself. However, if you have a large deck or other similar projects that you are thinking of doing, then hiring a contractor would probably be the best option.
One of the first things you should consider when you are looking for a contractor is the amount of time they can devote to your project. Do they need to start and finish the job in order to meet your timeline? Many people would rather hire someone that has done it all before, rather than someone that is only qualified to do one or two projects.

You can usually tell how much experience a contractor has by the location of their shop. If they are in the city, then you have probably seen them there. The old-fashioned method is to find a few local builders and ask them which deck building companies they recommend. Ask them why they think they did the work for them. Did they have any problems with the contractors or was the job completed exactly as they expected? If you were impressed with the answers you get, you can probably trust these contractors to build you a great new deck.
Before hiring anyone, make sure you check credentials and references. Finding out how long they have been in business is one way of finding out if they really do know what they are doing. You should also ask about their customer relations and sales experience. Remember that the deck you are building is going to be an extension of your home, so make sure that you work well with the contractor you choose. The last thing you want is to end up with a deck that you are unhappy with.
Once you have selected several contractors, start by having them visit your site to get a rough idea on what it looks like. Most contractors will come prepared with drawings and plans. This will help you to see exactly what it is they are proposing. Ask them about the materials they will be using and any special considerations that are relevant to your project. If they offer you a free deck design, by all means take it, but do not let them pressure you into signing a contract until you are fully satisfied with the designs.
Once you have visited the site and discussed your goals, it is time to start contacting the contractors. The best way to do this is to make a list of the contractors in your area along with their contact information. Then, go down to the local library and check out books on deck construction. Find several books that discuss various aspects of construction and get a general idea of how each contractor operates.
After visiting several contractors and reviewing several deck building books, you should have a pretty good idea of which one you want to work with. The next step is to research the background and experience of each contractor. This should include their long and recent history and references. If you find a contractor with multiple projects under their belt and multiple awards, you may feel comfortable with them. However, if you are working with a new deck builder, it is critical to find out how long they have been in business and whether or not they are members of the Professional Deck Builders Association. This information will help you to determine the credibility of the contractor.
In my opinion, the best deck builders are those who belong to trade associations and are memberships in good standing with the Better Business Bureau. There are many different types of contractors out there, so it is important to choose someone who has experience with a wide variety of structures. Ideally, you would like to choose a contractor that has completed work on projects like a new deck, commercial building, or other structure where you would like to have decking placed. Although the ideal candidate is someone who can finish just about any project, it is important to understand the time it will take for each individual to accomplish his or her goal. In my Breyer Construction reviews, I mention several different types of contractors including those who specialize in deck building, as well as others who can do any structure imaginable.