Roann,
I try to carry a wide variety of items for sale when I travel. I have Magic Armor and Spell Shield (and Bless, and Reflect Magic, and Elemental Shield, etc. etc.) potions for sale in large quantities. My normal price is one silver per level of the spell the potion represents (or double the production cost). You and/or Bjorn are welcome to find me at the next gathering and I am always happy to conduct business transactions large or small.
For reference, the Shield spell cannot be made into a potion, only a scroll.
-Lord Polare Lissenstine