Notwithstanding any other provision of this part, an agency with the approval of the legislative body of the community may acquire, by negotiation or other means, real property in a project area at any time after formulation of the preliminary plan for the area by the planning commission, and prior to the adoption of the redevelopment plan by the legislative body of the community, provided, however, that an agency may not exercise the power of eminent domain in connection with that acquisition prior to adoption of the redevelopment plan.