Nothing in section 471.345 shall be construed to prohibit Ramsey County from adopting a resolution, rule, regulation or ordinance which on an annual basis sets aside for awarding to small businesses a percentage of the value of the county’s anticipated total procurement of goods and services, including construction, otherwise subject to that section, and which uses either a negotiated price or bid contract procedure to award a procurement contract under a set-aside program allowed in this section. Any award based on a negotiated price shall not exceed by more than five percent the county’s estimated price for the goods and services if they were purchased in the open market and not under the set-aside program.