i kind of had this problem too, but this is what i do. take a 2liter bottle, like pepsi, and cut it in half. put in some fruit, i use cantelope, but im sure strawberries, grapes, etc. will work. then put the top into the bottom upside down, so it fits nice and tight. just put the bottle outside, and check back in a few hours. i usually catch between 5 to 10 a day. this will save u a lot of money, if u put out about 4 or 5 two liters. but if ud rather buy them in bulk, then i recommend this site
www.bigappleherp.com
im not sure if they ship to canada, but if they do id reccomend them. the fruitflies got here really fast, and what i like is that the container they come in continues to produce fruitflies for about 10 days. so after u feed the 100 that comes in the culture to ur pets, by then there will almost be another 100 in there
You can try to breed your own but its getting cold out which may make that impractical and its also messy and smelly. I ordered a batch of flies from www.carolina.com a long time ago and have never had to buy flies again. I also bought the medium from them and just make my own cultures from the original flies over and over again.