i had the same question and probably will just get another load of compost.don't know where you live but i get mine from the town of amherst compost facility. it was bought by the company (krantz). they raised the prices but still not bad.used it in the past.they will load a truck and sell it by the bag.

I would mix in an organic ready made fertilizer. The one I used last year came in pellet form in a bag. It was a combo of things like potash, bone meal, rock phosphate, etc. Compost itself is just one source of some nutrients. It's main use is making the soil nice and loose and ready for soil organisms. After planting, I use Miracle Grow spray once in a while.

I don't use anyone's compost in my food garden because I have no clue what was in it. Last organic bag I bought had half of an old glittery shoelace mixed in.