2k, 4k, or 8k?

I was talking with a friend recently about atmel AVR chips.  Specifically, he was looking at the ATtiny44.  This part has 4kB of flash, but it has two sister components with 2k and 8k as well.  These are the ATtiny24 and the ATtiny84, respectively.  My leaning is towards the higher flash, just because I'm lazy and like bootloaders:)  I decided to do some investigation on price to see where these chips are sitting.  I use Digi-Key's canada site, being in canada it's more convenient for me.  The ATtiny24 sells for $2.06, the ATtiny44 sells for $2.32, and the ATtiny84 sells for $3.13.  That first 2k is worth 26cents, the final 4k is worth 81 cents.  On a per kilobyte basis, the 4k in the '84 is almost twice as expensive as the 4k on the '44.