In the original comment, the person is talking about Black Swallow Living Soils. We (KIS) formulated a mix with them a number of years ago, but we are not making or selling that soil mix. As for the cost of the soil at KIS Organics, I figure that's worth addressing. First off, yes you can absolutely mix your own soil for less. When I first started in the industry that's why we began offering organic amendments. It was because I wanted to mix soils and experiment but you couldn't find anything under 50 lbs bags and I only needed a few lbs of each amendment. I fully support anyone who wants to mix their own soils. Shipping can be a total deal breaker too, soil is heavy and expensive to ship.I would never buy KIS or BAS soil. Both are very overpriced and overrated. You almost have to mix your own if your going to grow that way.
Now I've learned a lot over the past 15-20 years since starting KiS Organics and doing the podcast. When I first started I used online recipes and guessed at quantities. One thing I learned quickly is that online recipes are not accurate because everyone has a different compost source and you really need to formulate around the compost that you're using. Now when I formulate a soil for commercial production, it takes me about 2 years on average. That's how long it took for the Black Swallow Mix, and about how long it's taken now in Australia for a mix we are going to release soon. This is because there's a lot of testing that goes into it. You have to test every input for heavy metals and fertility (this is expensive). And then you need to mix a base soil and get the ratios right for optimal physical and biological properties. Then you soil test repeatedly to get the chemical/mineral ratios correct. And finally you need to run plant trials to make sure the soil tests are reflected in plant growth.
I cannot speak to Buildasoil or their process or pricing. I can only talk about KiS Organics. I know the folks that use our soils vs making their own do so either to save time or they like our data driven approach and want to know their soil will perform and is low in heavy metals. A lot of it goes to commercial facilities because we work closely with them on testing and analysis.
So yes, I totally get it if you feel it's too expensive, especially when you add in shipping costs to folks that are far away from us. But I do believe we have the highest quality commercially available soil on the market. I'd put it up against anything else out there.