I don't plan on buying a P407 board but found the P407 in several more places so I have hope for the E407.
Looks like one will need to shop for price on these new boards. I found the P407 for as high as $174.
Olimex has the H407 for 30 EUR, the E407 for 40 EUR and the P407 for 110 EUR. I hope the E407 is under $60 in the U.S.