Composting my own soil

I recently asked a question almost identical to this one. But I want to do an organic grow using subs Supersoil. I want to do 8-14 plants in anywhere from 50 to 100 gallon pots. I can't afford to buy 1400 gallons of Promix and amendments. So the question is if I compost that much regular outdoor dirt with all the amendments of Promix and Supersoil, would I be close to the actual thing?

You got some really good advice on a previous thread so......
You might want to grow all these plants but if you can't then you should cut down your numbers. Just a thought.

No. Like was said before...

ProMix is primarily peat moss (organic material). Healthy yard soil is typically some type of loam (equal parts silt, clay, and sand, plus maybe 5% organic matter). One drains well, one doesn't. One is a soilless mix, one is soil.

It is absolutely possible to ammend native soil and grow healthy plants in it (farmers do this every day) but you're going to have to ditch the idea of sticking with someone else's recipe. Also, this only works if you are planting directly into the ground, not in pots. Regular garden soil (loam) does not drain or aerate well enough to be used in pots.