Hi Sarah, TC has a lovely birth community!
Going rate for doulas here is $300-600, depending on experience. You might be able to find a brand new doula doing her first few certification births for around $200.
Cost-of-living is pretty good here! I understand about TC, we have a friend who keeps trying to get my DH to move up there to earn 1/2 of what DH earns here, with the promise that "it's a really good salary for Traverse City," but we also know the COL is so high!
If you end up staying in TC, check with your midwife about cost. Some will do repeat clients for the same price they charged for the first birth.
Feel free to PM me if you want more info as your potential move draws closer. I also had a home birth here with a doula, my midwife, my 2.5 year old (and his support person) present and I'd be happy to share info if you need it.