Thanks to Paula for this Frugal Baby Tip!
I got terry at Walmart of all places! It's 80/20 cotton poly and I love the prefolds I've made out of it. My soaker is two layers of microfiber toweling...also at Walmart. Those blue or white 14x14 ones in the auto detailing department...8 for less than $5. I do have to "piece" the soaker parts to get them long enough for the size prefold I make (about 17 inches) but I overlap the seams and triple zig-zag them so you can't tell by the time you've got all the layers together.