From a few guys I know that went through the Envoy program, they ended up using about seven months of GI Bill money and the rest Envoy took care of. Envoy is using Coastal in both San Diego an in Texas now. Not a bad deal when you consider you don't have to pay anything out of pocket and you still get their full bonus. It is also pretty fast as it is in their best interest to get you qualified quickly.
Don't feel like Envoy is your only option though. PSA and Peidmont both have rotor to regional programs in the works. That haven't fully worked out the details yet and which schools they will be partnered with, but if their bases work better for you and than Envoy's then it would be worth a call to their recruiters. I'm pretty sure I'm heading to PSA and if you have questions about that airline feel free to shoot me a PM. I'm Navy rotary with quite a few fixed wing qualifications so I'm not using one of the programs, but I've spoken with PSA's president and their recruiter for their rotor program and they are looking for good pilots.
All the best, Tester