Well Canadian dealers usually have their stock ordered well ahead and paid for ahead of time, SO whoever bought stock when our dollar was below parity has to charge more, or try to.
I am looking at getting some manual lenses but only after I spring for a nice Katz Eye viewfinder screen. I am not a fan of the standard Pentax DSLR one in the K-5.
As for deals, I keep browsing Craigslist, buy and sells, classifieds etc for some little old lady looking to sell off some pile of old Pentax gear and hope she doesn't know what she's getting rid of.
I've heard of people getting the A* 135mm Prime manual lense (retails for almost $1500+ used when you can find them) along with other lenses and gear for $200-$300!!