While I was at Canadian Tire today picking up a new filter for my humidifier, I saw these 2-pack CFL light bulbs for $3.99 and 4-pack CFL for $7.99. But right beside the bin, there were these $2 off coupons from Ontario Power Authority for any CFL light bulbs. Without having to do too much math, I picked up a 2-pack CFL at $2.

You are only allowed to use one coupon on each pack of CFL that you purchase, but you are allowed to use up to 5 coupons, so you can still get up to 10 of them at $10 + tax.