...if you want a lightweight, but still gold, setting, that can be found in the ~$150 range. not from Stuller or Adwar, but they are out there. they're not forever pieces, but they're still pretty.

i'd start with http://stores.ebay.com/LiebCor

a 10kt yellow gold setting for an 8mm round is $90, including shipping, and they'll set your stone for you for a few more dollars. (i can't remember if it was $5 or $8?)

or $80 for a 6-7mm round http://cgi.ebay.com/4-PRONG-SOLITAIRE-SE...=item1e52c7295d