Smaller resellers play a part. Small retailers have to scale to their clientele but are handy for those not wishing to get lost in the supermarket.
When talking about livestock or natural product resale, the search engine asks if perhaps you mean sellers not resellers. Similarly, it seems wrong to talk about pig retailers but perhaps pork retailers (?) though I think the retail of the hock or speck comes when you're in Coles or Woolies
And amethyst retailers doesn't sound sufficiently new age.
If you light on a certain product then the use of 'retail' and 'resale' could be seen as interchangeable; even if usage is generally uncommon.