Blu ray drives have dropped in price, at least from a couple years back. ive been looking lately for one too and from what ive seen it's a matter of around $20 extra to get a Bluray burner instead of just a BluRay reader.
Do you like using discs to back things up? If not, then you might not even bother with the BR Writer, rather just the player.
But depending on where you buy it from, if its only a few bucks extra to get the burner, just get it imo.
Im pretty sure blu ray drives are backwards compatible with CD's/DVD's