Press your seams in opposite directions and pinning exactly in the seam line and then a pin on each side of that pin. As I sew up to the first pin I remove it and when I am one stitch from the center pin, I remove it and then the third pin. I find that this works for me. I hate frogging (rip-it, rip-it).
I found a walking foot for my featherweight at the Houston quilt show and, while I don't remember exactly how much I paid, it was was under $50. It works great. Hope this helps.