For gaming only purposes should I get the i3-8100 for $150 CDN, the i3-8350K for $219 CDN, or the i5-8400 for $235 CDN?
What games are you playing? What refresh rate is your monitor? What is your GPU? What is your motherboard? What is your budget? Would you be willing to overclock and invest in a cpu cooler? What case are you using for the PC?
At least tell us what you're using the computer for. All that other information isn't necessary unless you want us to give you very detailed responses.
I will be playing OW, R6, CSGO, Fortnite. My monitor is 75hz. havent bought a gpu but looking for a 1060 or a 580 once the prices drop. I am willing to overclock. For a case I am using a Phanteks p400 TG
At 75Hz I would say the I5 8400 would be the best bet. It has 6 cores and a good clock speed so it should handle that refresh rate no problem. The added cores will give better performance ins some tasks but not all. The I3 8350K when overclocked can be a little ripper but for 75Hz it really isn't needed.
Where I live, the 8350k is less expensive so any other thoughts on that?
I recently did a build with it and it is a little monster. With 4 cores it is comparable to a Kaby lake I5 and it overclocks really well. You will need an aftermarket cooler but a decent HSF will keep it plenty cool and not break the bank. I highly recommend it if you can get it for a good price.
Get i5 8400 it's good.
Maybe you could buy a APU in the meantime and upgrade when you can. the APU can run all those games at decent frame rates.