***Level 1 gamer alert*** please be nice.
1) What is the cheapest place for computer accessories? (mechanical keyboards, mouse, screen, etc)
Canada? I wouldn't know anymore. Their retail market had a big upheaval when NCIX went to crap.
I like Newegg because the website is easy to use. So I'll often use it as a starting point.
If you know what you're looking for, you can punch it into PCPartpicker.com and it will compare prices for you.
2) what's the cheapest way to get a PC with a 1080 graphics card?
I guess that would describe your budget then.
There's a couple desktops on newegg.ca with 1080's in them for $1600. So that's probably as good a place to start figuring out the budget.
CyberpowerPC Gaming Desktop Gamer Master 2787X Ryzen 7 2nd Gen 2700X (3.70 GHz) 8 GB DDR4 1 TB HDD 240 GB SSD NVIDIA GeForce GTX 1080 Windows 10 Home 64-Bit - Newegg.ca
What I would do is start picking parts individually and see if you can build it cheaper/better for the same money. You might not be able to, the prices are kinda nutty these days.
But if you're just interested in buying one, compare it to other places.
You might also consider the RTX 2070, the Vega 64, and the GTX 1070 ti. All are pretty well around the 1080.
The Vega 64 is just a little behind the 1080, and the 1070 ti just a little behind the Vega 64. But mostly within 5-10% of each other though some games vary much wider. The 2070 is slightly faster than the 1080.
Depends what kinda monitor resolution you're looking into for which one I'd pick.