Sometimes, the grocery store!
And saw this Out in the garden department. I can buy packer briskets, oaxaca cheese, 2lbs of seedless grapes, and now Fox Farm weed farming stuffs in one location. 🫠 The crazy thing about this...10-15 years ago around here a cop seeing a bag of Fox Farm in a car during a traffic stop was...
budbuilders.org
Amazon, True Value Hardware, or Ace Hardware for Coast of Maine Stonington soil and other brands like Roots or Fox Farm. The two hardware stores with ship to store features are often the best deal if there's a store near you.
Ebay, in particular a seller who goes by Spreetail, has some of the best deals on Roots soil brands. I can vouch for this being clean, warehouse stored, bug free soil
www.ebay.com
Another good ebay seller is Esbenshades Garden Center. They're also on Amazon
www.ebay.com
Most online grow stores charge freight shipping rates on soils but sometimes there's deals with free shipping at Grow Green Michigan's Dank Deals
GrowGreenMI.com - The World's Largest Hydro Store! Thousands of items in stock and DANK DEALS on the best brands
growgreenmi.com
I have seen Promix red bales at Walmart too.
Sometimes when using google shop for a particular brand a rare deal may pop up.
For example, I've been wanting to try GreenGro Pride Lands soil. I've seen Stoney use their amendments or teas and he likes them so the soil has been on my radar.
Stonington got a little spendy on Amazon so I started shopping for alternatives.
My first choice was Roots GreenFields and I bought it off Ebay.
But days later I found a deal on Pride Lands so I ordered it. I fully expect this order to be cancelled though because it only charged me $26 to ship 5 bags and it's usually a freight rate of like $200-$400. We'll see what happens but at least I have the Greenfields already if the Pride Lands gets cancelled