Welcome to TF. I am a past delivery skipper 20-years out of the business, though have zero experience in the Great Lakes. A few nuggets:
1. There are many, many people with USCG licenses out there and not much experience. Many with claimed experience exaggerate their time, skills, and responsibilities (crew instead of captain).
2. My sense is $400-$500 per day will get a captain and one crew. Might be a bit less there than along the California coast where I delivered - there are many more qualified captains in the east than the west.
3. General rule I used was fees for captain/crew were about 50% of the total delivery cost. This proved remarkably accurate.
4. Probably the most common question people ask about hiring a delivery captain is whether they charge when weather or mechanical failure causes the boat to stop. For experienced captains, the answer is "the meter keeps ticking-over." A decent captain will have decent mechanical skills and likely play a big role in getting the problem fixed; or is doing other maintenance (I've done dozens of oil changes on customer's boats). If I was confronted by a delay of more than a couple days, I often had another boat I could move. But in the end, if I'm on your boat and not at home cuddled with my dear Cheryll, I was on-the-clock. I think that's fair - anyone who says otherwise hasn't been doing it very long.
5. A decent captain will most likely deliver the boat to you in better condition than he departed. He will fix a few things along the way, and give you a very good report on the operating characteristics of the vessel Something to think about when you compare to the el-cheapo guy on the dock with a puffed-up USCG ticket, salty-sounding stories, a Greek Fisherman's hat, and a corn-cob pipe
Although I don't know this exact market, I would figure $2k-$3k/week for fees, $2k-$3k/week for expenses (Fuel, berth, transit/travel, provisions, supplies, etc.). If it's indeed a 6-8 week run, might be as low as $30k, but it could easily run to $40k I suppose. But I'd be curious what you end up with. And I'd be curious if a delivery makes sense economically. You haven't stated the boat, but often people see boats are cheaper in Florida - they are......for a reason.
Here's a 1999 Willard 40 in Wisconsin. At $250k, sounds a bit expensive. But she's been stored in a climate controlled warehouse each winter and likely looks nearly new. Put the same boat in Florida for 22 years and it would have chalky gelcoat and fabrics would be shot. I wouldn't be surprised if a $30k-$50k refit would be the difference......and a year of doing the work
Good luck -
Peter