With that being the scale your looking for I would search around for a recipe to make your own soil.
3.8cu ft bale of [COLOR=#009900 !important]
premier[/COLOR]
hort peat poss $14
40lb bag of composted organic forest hummus and chicken poo( or was it horse or cow, i believe they mightve even had a choice of all 3) $4
40lb bag of dolomitic lime $4
perlite (find it anywhere for cheap)
40lb organic worm castings $4
All credit to Subcool.I in know way shape or form own this idea
cheap! these few materials can provide everything your grow needs for a long time. say no to expensive commercial mixes and<span style="color: rgb(51, 51, 51); background-color: rgb(250, 250, 250);">[video=youtube;a-iIi3CzTNY]
https://www.youtube.com/watch?v=a-iIi3CzTNY[/video]