Well, walking is probably the cheapest.
Working your passage.
take amtrack http://www.amtrak.com/servlet/ContentServer?pagename=Amtrak/HomePage
See www.nfta.com for Buffalo Bus schedule to airport in addition to buss from Toronto to Buffalo Bus station
Walking is the obvious way, but probably takes longer than you like. Driving a car is pretty inexpensive if you have one. A bus would be the next alternative.
Hitch Hike
Least expensive usually translates to least effective. The cheapest choice for damp-proofing a basement is usually a coating of waterproofing paint, like Drylok sealer on the interior masonry walls.
probably bus or amtrak
Walk.
Yes, car insurance for a teen in California is expensive. But then, car insurance for a teen driver is expensive everywhere. The least expensive way would be to them to your existing policy, you may get a discount.
Toronto........ All the way
There are portable water ionizers that cost under $100 dollars.
Effectiveness is about doing what your suppose to do, the right way. While efficiency is doing things in a way that is favorable concerning a certain restriction, such as the least expensive way.