I am from Toronto and had the same problem with finding stuff in bulk for Welcome Bags.
I really wanted to include small packs of medicine and I checked out minimus.biz < they actually have ANYTHING you could ever need in travel/individual sizes. Prices are USD and I had to pay shipping, but you can't find this stuff in Canada (such as the prepackaged Advil, etc.).
I sent out an email months ago when everyone was booking as for shoe sizes as I arranged with Old Navy to be able to buy 80 pairs of flip flops during their $1 sale. I wanted to ensure everyone had their proper size so they could actually use them!
I have 80 people attending my wedding, and have a bag per couple. I am also doing kids bags. I have 5 children attending so I am giving them colouring books and crayons (Dollarama), flip flops, shovel and pail (Superstore), candy, sunscreen, and probably a little game from Dollarama.
In my Welcome Bags:
Bags - Creative Bags in Pickering, ON/also online
Wedding Timeline - Etsy
Door Hangers - Etsy
Advil, Tylenol, Pepto, Wet Ones Wipes, Mini Aloe - www.minimus.biz
Deck of Cards - Costco
Flip Flops - $1 sale at Old Navy
Small bag of chips - Costco
Candy Bag - Bulk Barn
I think my bags will be $15 or less each.
It's a good time to buy stuff right now for Destination Weddings as everything is going on sale at the end of summer!
Hope this helps