mate you arent getting them at 2 - 3 gp each.. nobody is selling these to you for less than npcs sell them for.
I'd like to get a perfect-condition 1987 Porsche 911 for £5k IRL, and that's not happening either. Best best is to become a member of the Mage's guild (if you aren't already) and then at least you can get them for less than the base NPC price. Mark runes for all the magery shops, do the rounds, you'll get all the shade you could want in half an hour or less.