I think it now varies by province.
For all of Canada the federal government applies an excise tax at $1.572 per kilogram.
Rates of excise duty imposed on beer, cannabis, spirits, tobacco, vaping, and wine products
www.canada.ca
But then you have to add the provincial taxes which is where things are getting clamped down.
It looks like Saskatchewan is going to be a no go for whole leaf anymore, they are charging tax based at the same rates as tobacco products $0.35 per gram, more than the tax on cigarettes
Read about The Tobacco Tax Act, 1998, which imposes a tax on purchasers and importers of tobacco products in Saskatchewan.
www.saskatchewan.ca
"Effective 12:01 a.m., March 24, 2022, the tax rate for cigarettes and cigarette sticks is 29 cents per stick. Smokeless tobacco and other tobacco (including raw leaf) is 35 cents per gram. Tax on heated tobacco products is 21.8 cents per unit (stick, capsule or cartridge)."
In Ontario the law allows for importing 3kg, but doesn't state a yearly limit. There is no provincial tax of whole leaf from what I can see. Maybe the 15kg applies to your total yearly amount you can process from your 3kg imports.
Learn about raw leaf tobacco regulation in Ontario including who needs to register and report production and distribution of raw leaf tobacco and personal use exemptions. This online book has multiple pages. Please click on the Table of Contents link above for additional information related to...
www.ontario.ca
"The Tobacco Tax Act provides for exemptions that allow an individual to:
produce and process for his or her own personal use, and not for sale, up to 15 kilograms of raw leaf tobacco per calendar year
buy up to 3 kilograms of raw leaf tobacco for his or her own personal use
import up to 3 kilograms of raw leaf tobacco for his or her own personal use
export up to 3 kilograms of raw leaf tobacco for his or her own personal use
transport up to 5 kilograms of raw leaf tobacco for his or her own or another individual's personal use."
In Quebec it's just as bad it looks like. $0.149 per gram of raw leaf
www.legisquebec.gouv.qc.ca
You can try to use the form I was sent with my order to get a reassessment.
It looks like the era of whole leaf in Canada is coming to an end
I just moved to New Brunswick where there doesn't appear to be a limit or tax from what I see, its not considered a tobacco product here.