Takes a lot of tools and hard work. Compactor, chop saw, skid steer or other excavation equipment.
Where in Maine are you? Your area will have an effect on your price. Probably higher rates near the big pond.
Some guys say $10-$12 or more per sq ft. There are variables to consider though -- natural stone takes longer than pavers, some pavers are around $2 sq ft, other are upwards of $5 sq. ft. Fancier patterns are also more time consuming and will require more cutting. That's why I think hourly rate is safest.
Your labor rate should be a constant number. Laborers are billed at $xx.00 per hour, foreman at $yy.00 per hour. What should change is that you need to add for your equipment. If you need to rent equipment, add the rental fee plus some markup for overhead & profit, or if you are using all of your own equipment, each piece should have an assigned value or cost per hour just like you assign a number to labor.
This place is a pretty big project(for me)702sq. ft. patio with pavers and a walkway to the beach and the client has money. One of his summer rentals that he get 2500 a week for. Haven't decided what to do with the walkway to beach yet. I'm still interested in the truck loader. I hope to get it on or by this weekend. Are you around this weekend?