@Herder
I contacted two suppliers and they wanted to sell for like $10 a piece for 40 pcs...
@leofoe
AFAIK you can mix them, but you'd have to put the fast page ones on the first bank since that's the one tested at POST to decide burst/no burst. I've got a set of FPs lying around for months but have yet to put them in (I'd prefer getting SCs so I wouldn't have to pull out the first bank).