A regional common market model featuring electricity-green certificate-carbon synergies is proposed for high-penetration renewable energy sending-end regions, where inelastic intra-provincial demand and lower regional market concentration lead to cost shifting. This model integrates power, green certificate, and carbon trading across inter-and intra-provincial markets, eliminating generators' speculative arbitrage arising from cost inversion under decoupled two-tier markets. A generalized Nash game is introduced to allocate the environmental value of green power, ensuring equitable benefit sharing across regions. Case studies demonstrate that this coordinated multi-energy and multi-rights trading mechanism enhances intra-provincial demand price elasticity, reduces system costs and carbon emissions, and significantly improves renewable energy utilization, offering a market-oriented and enduring solution for green power development.