Pay cash.
50% down.
30% on first inspection.
Final payment on final inspection.
Make sure the permits are pulled and a performance bond is posted with your name on it.
Most roofers will offer at least a 10% discount if paid ingreen foldie stuff.
L
We had our pool redone, got a discount for cash and 50% required up front the remaining 50% due upon finish and inspection.
Same for the roof when we had it done last year.