If you have the storage place, i would just get an entire pallet of salt. I know for sure we can dropship 36 buckets of kent on a pallet to you with free shipping. I can probably get AquaCraft brand or Marine Enterprise to do the same as well.
On the sand, we can have a pallet dropshipped for about 390 dollars, plus or minus, depends if you need a life gate too. If you don't have a place with a fork lift, you'll want to pay the 90 dollars for the lift gate so they'll drop the pallet off instead of hand unloading. The pallet charge is the same on the pallet regardless of bags, up to 70 bags. So i would recommend getting all 70 since you don't pay extra on shipping.
thanks