I've read elsewhere (can't remember where) that it's $60 for Fido, and when I called yesterday (had a login issue but asked about this too) she said my account was fine and I don't pay $80. But call centre drones can be wrong.
But if you do have to upgrade your plan to qualify:
The carriers subsidise $480 or so, so if you have to pay $20+/mo more for a plan it makes more sense to buy outright, if you have to pay less than $20/mo more for a plan it makes more sense to buy from the carrier.
EDIT: Looks like the $80 for Fido might be right for new customers at least, on Fido's website to get the $450 discount it says you have to have an $80 plan.
https://www.fido.ca/web/page/portal/...lyPlans/Group3
Plus I didn't account for any discount you get by bringing your own device, Fido offers 10% discount.