However, there are still some problems that need to be solved in this process. And an inexplicable pricing decision would actually punish customers who first purchased PCs with Windows 8 preinstalled. Here are the details.
Whose nickel is it if, during demolition, your builder finds asbestos-wrapped ductwork that was hidden during the bidding process. The less specific your plans and specs are, the less likely it is that competitive bids will be comparing 'apples to apples'. Be sure that your design work truly defines the 'apples' you want, not just some "apples". And please understand that design work prepared for competitive bidding should be more specific, and therefore more costly to produce.
Since numerous companies are pricing out the work you need to be assured that they truly understand the 'apples'. So often we see or hear about a project that proceeded with another builder that went sour because a loose design became a loose agreement, which then became an unacceptable solution (i. too costly; poor design; substandard installation; etc. ) Or, worse yet, a project that was done on a time-and-material basis, with little or no cost or design controls in place to protect the client.
So research your builders well; research your own design well.