Morning glories or HBWR seeds are your best bet for a cheap, legal, easily obtainable drug - just make sure to get seeds that haven't been sprayed or treated with chemicals/pesticides.
You'll have to do some research of your own to find vendors, but there are a WIDE variety of synthetic psychedelics that are legal in Canada and can be ordered online. Unfortunately we can't discuss specific sources here on Bluelight or direct you to one, but if you do some research and googling, they're not that hard to find. Some of the most popular synthetic psychedelics that are legal in Canada are the 2Cs (2C-E has a reputation as the most intense of the group but there are a whole bunch of 'em - they are closely related to mescaline, the main active drug in peyote and other psychedelic cacti) and 4-ACO-DMT (which is closely related to psilocin, the main active drug in shrooms).
You could also extract your own DMT - it's not legal to extract (in the US, at least; I assume it's also scheduled in Canada), but there are plenty of common plants (mimosa hostilis root bark is the most convenient/popular for extractions) that contain DMT, and it's really easy to do - the only part that's even slightly hairy in my opinion is having to work with lye, which will burn painfully if it touches your skin (remember the soap scene in Fight Club? That was lye), but if you are careful and wear rubber gloves, it's really not difficult.