So, I went to the Michael's store here in Thunder Bay and let me tell you, only a truly insane person would pay those prices, so I promptly left. lol I had been looking into buying Mod Podge, but at that price, I'd do without.
I then decided to look online to see if anyone had revealed how to make your own and low and behold I found it here: http://doityourselfdivas.blogspot.ca/2011/09/diy-mod-podge.html
I had bought a large bottle of white glue from Canadian Tire, that was way cheaper than even a small bottle of Mod Podge at Michael's, and my son washed out a recently emptied jar of jam and I was all set. Interesting that you can get full strength glue for way cheaper than watered down glue.