In this paper, a heuristic approach is considered for the distributed generator (DG) placement to minimize system loss. The constriction-factor particle swarm optimization method is used as an optimization tool for the planning problem. A Monte-Carlo-simulation-based probabilistic load flow is proposed to find the unavailability of the DGs in the planning problem. The net-present-value analysis of the planning in electricity-market scenario is carried out for biomass, wind, solar-photovoltaic, and diesel-engine DGs to see their viability under bilateral- and competitive market scenarios. Various factors such as profit, incentives on capital, replacement, startup, operation, and maintenance costs have been taken into account. The proposed market-based analysis is simple and generic, and can provide choices to the distribution utilities to select DGs under various constraints. The effectiveness of the proposed method is tested on 16-, 33-, and 69-bus distribution systems, and results are compared with an improved analytical method suggested in literature.