Roots Organic 707

Anyone using roots organic 707 soil? I currently ordered some new beans, in the past i've used the soil, germinating the seeds until they shoot the white tail and placing them in directly in 707 soil and add no nutrients for a week or two, they take very well. anyone have any other suggestions for starting soil, I know 707 has a good mix to start, but its getting pricey... I've also used pro mix, but thats also pricey and has no feeds etc.