This is what happens in nearly every situation in which a clearly defined set of working drawings and detailed specifications are not identified by all contractors. First, you should never have more than three qualified contractor estimate any project. Spending the time and effort dealing with five contractors is usually a waste of time and energy. Second, give each contractor a written, detailed list of all included items to be incorporated into the proposal. Include product manufacturer numbers to be as specific as possible.
Many contractors prefer to just deal with product allowances rather than pricing specific products.
The vast majority of the time, the answer is no. Typically, homeowners who sign contracts with contractors using allowance figures end up paying substantially more for those products when final decisions are made on selections. This allows the total sales price to be lower than a contractor who has priced more expensive products. Although one contractor may appear to be lower priced, it is not uncommon for that contractor to actually have a higher price after final overages from contract allowances are figured into the final change orders. A remodeler has to provide you with a level of quality workmanship and services to ensure your satisfaction and happiness throughout the complicated remodeling process.