The guys I used 'my People'
(usautoimport.ca) have a basic rate of $750 to do the following (some of it isn't needed in the case of private sales of classic cars) ...
1. Confirm with RIV (Registrar of Imported Vehicles) that your vehicle is admissible into Canada.
2. Contact the dealership that sold you the car to ensure all of the proper documents are present.
3. Acquire the necessary recall letter for your vehicle.
4. Hand deliver your documents to US Customs for pre-clearance.
5. Canada Form 1
6. Provide safe insured transport of your vehicle to Canada.
7. Clear your vehicle through US Customs.
8. Present your vehicle to Canada Customs for inspection.
9. Remit all applicable taxes, duties, and fees to Canada Customs.
10. Complete any required modifications.
11. Convert speedometer into km/h
12. Have your vehicle inspected, to complete RIV process.
13. Complete an Ontario Safety Inspection and E-Test if required.
14. Prepare the Licensing (Ontario Ownership and License Plates)
15. A quick car wash before you pick up your car.
Transportation was extra, I think around $800 door to door, and I didn't have them wash the car, do the speedo conversion, nor mount the plates (I didn't want them trying to drill holes for the front plate! ;-)
I didn't have to worry about incomplete paperwork and potentially making multiple trips to the border - it was worth the extra few $$$ to avoid the hassles and to have the car insured from pick-up to drop-off.