Under the current plans, the funding from general reserves could be used for promotion, licences, legal advice, traffic management, cleaning, security and unexpected costs.
The council had also considered several other locations for the market, including Freight House, Webster Way, Bellingham Lane and Mill Hall car parks.
However, the Market Place Car Park was deemed the most likely location to benefit businesses and attract visitors.
Meeting papers state that a market operator, commencement date, operating hours, layout and management arrangements are yet to be agreed.