A new model for the cost of production of heavy-ion fusion targets in dedicated on-site target factories is presented for power plants. The model treats single- and double-shell direct-drive and generic indirect-drive targets. Target factory capital costs, nontritium target materials costs, and target factory operations and maintenance costs are estimated for target substructures such as fuel capsules, radiation cases, and driver energy absorption regions. These individual estimates are combined to obtain the total target cost. Realistic scaling of target costs with variations of such important performance parameters as target factory production capacity and driver pulse energy is emphasized. The model can be modified and used for other inertial fusion drivers and fuels. Typical target cost estimates fall into the range of $0.25 to 0.45 per target. The estimated target cost contribution to the total cost of production of electric power is typically ∼4 to 7 mill/kW·h.