Mercury 2.5 Preview and Ling 3.0 Flash Fin are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Mercury 2.5 Preview, from inception, has a 260,000-token context window and is priced at $0.04/M tokens input, $0.15/M tokens output on OpenRouter.
Ling 3.0 Flash Fin, from inclusionai, has a 262,144-token context window and is priced by the provider serving it on OpenRouter.