In content delivery services, quality of service is greatly affected by the resources provided by the underlying overlay P2P. In order to maintain the level of resources acquired, soliciting peers' resources contributions by giving explicit remunerations is a feasible solution. From the service providers' perspectives, the remuneration should be minimized as long as the guaranteed services are fulfilled for all users. We consider a model defining the objective function to minimize this cost in service provision and a distributed and cost-efficient resource acquisition algorithm. Our results show that, in a network of the heterogeneous peers with limited local information, the service availability can be enhanced by appropriate resource acquisition schemes even in a heavily loaded network and the number of resource providers can be controlled by applying appropriate cost model.