Square's continual string of $40 portable games paints the company in a rather poor light, I think.
Honestly, deals on Fes will be few and far between. Its an Atlus title so the print run will be microscopic as it is -- and its releasing at a budget price! Use some Best Buy Reward Zone dollars or something, its going to be highly worthwhile.
If you're really pinching pennies, Amazon is probably the best bet since there's neither tax nor shipping. But, like most Atlus games, don't expect local gaming chains to have it if you didn't pre-order it.