For the Cloud Forest, you're looking at roughly $100-$150 for a day trip.
Here's a site that's $115 for a 12 hour trip.
For Avenue of the Volcanoes, I don't think it's possible to see it all in one day unless you're in a plane or something. You can check out portions of the "Avenue" though in one day.
This website is listing tours for Cotopaxi Volcano at $45.