If both parents have the albino gene, which they do if they are expressively albino, then at least a portion of the fry should turn out albino.
As it happens, they're not terribly common but quite so wherever they are found. Around here they range from $20 (for adults) to a buck fifty (for teeny 1"ers) and I would consider them common. I paid the $1.50 each for my group and if I'd paid more I would have been quite pissed since just like they're naturally colored brothers and sisters they're very aggressive toward eachother. The group I bought whittled itself down to a single pair which produced 100% albino fry for two years before I decided to give them away.
I considered them a plus over the normally colored auratus simply because I don't fancy the muddy coloring of adult male auratus.