After referring to the IP-DiffServ adaptive pricing mechanism of NSF CAREER, this paper presents an optimal adaptive resource pricing mechanism on the base of market and plan. Based on the service plan and service layout, it prices the service class by providing the users more performances with lower cost and by making ISP win the most benefits. While calculating user perceived benefit, the burden factor is taken into account, then it can lead to an orderly distributed traffic according to the service plan. Experimental results indicate that the improvement to the value evaluation formula of service class of NSF CARRER is reasonable and effective.