Same thing happened to me, except not only did they not inform me of the price increase, they just automatically charged me. $523 to ship economy to Florida, instead of the original quote of $310.
I didn't even bother to question them or fight them on it though as it was already done when I was on my business trip and I just said "screw it". Once I use my P1 points on either Ripley or Paul Atreides, I'm done buying from them. I refuse to PO either of them though as I don't want another situation where they give me a shipping cost estimate and then blow it up when it's time to ship. I'll only buy something in stock with the shipping cost already calculated. No more surprises.