They will sell you 1 bottle if that is what you want.
and another west coast source is -
Richards packaging
I'm sure as in everything, there may be minute differences that make or break a product for some, but woozies are pretty consistent. If you are looking for small quantities, check out the above links.
leener's looks like a cool site for lots for niche food making. Woozy bottles at that site are a little more expensive than the other sites. Even including shipping, I can usually get them for .85-.90 per bottle. And they are available in 10 oz size for about the same price.
I was looking at the mustard kits though............got my interest.........