Quite a while ago (long before I had heard of Ashas or Moissanite) I bought trillion cut green amethyst/prasiolite and snap tite posts from him. He has both an ebay store & a website. If I remember correctly the prices aren't always the same, so you'll want to check out both.
The snap-tite settings were snap-tite settings. I'm really not all that crazy about them but for my purposes they worked. The color and clarity of the stones were good - in fact I was told they were a marked improvement from a set of earrings that was sent back to amazon.
So for around $15-20 I was able to make a set of earrings to match my friends necklace. She didn't feel uncomfortable with the amount of money I spent and they're still worn today.