I was somewhat discouraged to find out that putting an external 1Mx16 flash chip on my AT91R40008 board was going to cost more than the 40008 (around $20 in singles from digikey). Then I found the Toshiba TC58FVB160AFT 70ns part from digikey for $3.24 singles/digikey and am happier. Same pinout/package as the atmel part.
I think this is a better solution than the AT91FR40162 part in a 121 ball BGA package for small/cheap prototyping runs as it allows you to use a lower cost board house and have some possibility of correcting design flaws.
Still, I am curious for the large price difference between say the atmel AT49BV161T-70TI at $20.36 and the Toshiba TC58FVB160AFT at $3.24. Am I missing something in the specs?