Steam is currently having their summer sale, and has their Silent Hunter titles at $5US each. In an attempt to keep up with the Jones, Amazon has now lowered their prices on the same titles, plus ONE... SH4 Gold Edition download is $5 US. It'd take you $10 US to get the equivalent at Steam. I have no idea how long this will last... Be sure and shop through the site's portal here
http://www.subsim.com/store.html and help support SubSim!
I have no idea if the Canucks or the Brits have similar savings...