Check out the Cufca site and get a few quotes done.
http://www.cufca.ca/home_e.php
That's the Canadian Urethane constractors site, on the top left there's a tab to find a contractor, Ontario has a big selection.
In theory I've seen the average can be anywhere from a buck a board foot to $2.50+. A board foot is 12" x 12" x 1" of thickness. I'm going to go on a limb and guess your contractor quoted you on 3" thick at that square footage so that would be in the range that I've seen. Question is was it 2lbs density foam, closed cell.
The DYI kits are good for smaller arear and if you want to do the job in sections. a typical 600 kits like the tiger foam, rivenco, Nuco, froth pack etc etc will yield around 500 to 600 board feet. It's a temperature sensitive product since it's in a pressurised container so you want to make sure you shake the kits really well and keep them at 27 degree C or as close as you can. You will lose allot of yeild if you dont shake the kits or keep them in the cold.
So that being said, what size is the area you are planning on shooting?
Foam is a tricky business cause allot of people think it's cheaper to do it yourself but there's some contractors out there that offer really good pricing and they come in and do it for you. Rest assured that it's worth every penny.
Let me know if you need any help and I'll be happy to help.