After I get the concrete block in place and I'm ready for the core fill, I can get a truck to come and pour directly for around $500. Premixed, pour-in-place.
Or I can do it myself by buying the materials, mixing with the cement mixer, and pouring it one load at a time.
8 bags of type I Portland (~ 800 lb)
3/4 cu yd. of pea rock (~2800 lb)
3/4 cu yd of sand (~2100 lb)
And then the humping of a couple of tons of rock and sand to the front of the house.