My first suggestion would be to check your local shops. If you’re looking for things like sand, charcoal, etc. then you can probably find those things at a hardware store. They don’t have to come from a witchy store! 
I don’t tend to buy things online so I’m not really any help 
but you may want to check and see if our Coven Member Shops 
has anything you’re needing. That way you’re getting what you need and supporting members of the coven, too!