The answer to this question lies in the quality you expect. The manufacturer that you have prepared your bid specifications will submit specifications that call for their method of construction. If a manufacturer that employs questionable construction methods prepares your bid specifications, you have no protection against use of those shoddy methods during the actual construction of the garments.
If your bid specs offer you no protection, and your school requires you take the lowest bid meeting specifications, then you have made yourself very vulnerable. By using bid specifications that call for the highest standards, and then by holding all manufacturers to those standards, you are assured of receiving the quality of uniform you demand.
By using the proper bid specifications you will not be a victim of low ball pricing, but rather you are assured of receiving a uniform that meets your specifications. Remember, if the sample submitted does not meet the CONSTRUCTIONSPECIFICATIONS you sent out, the bid should be rejected. If you feel that any deviation from the construction specifications exceeds your request, you also have the right to accept any deviation, this decision is totally up to your organization.