What jenn said. I have the Tikal PM and I adore it, but it's not a bag for school or work, it's for going out, IMO.
As for the price, may have something to do with the hardware, not only in the turnlock closure but also the rings sewn into the shoulder strap. Also, the canvas is treated a little differently, it's actually much softer than on other bags. I love it; don't regret it a bit. And it's roomy enough to hold my Koala wallet, my small agenda, cellphone, keys, and lipstick.