Just the thread title...
I've looked everywhere.... how much are empty bottles? (glass ones?) -- how much do they weigh?
Ultimate Equipment. Page 60. Fourth Down on the Left.
Or here, in case anybody searches for this topic later and actually would like an answer better than: "Want to know how much a potion flask costs? Buy a $40 book!" :
http://paizo.com/pathfinderRPG/prd/equipment.html
Yeah the reason why I posted that was it was right in front of me and my internet wouldn't go to the PRD or d20pfsrd.