I have never understood how people (so often people you hardly know) can ask you to spend your money and, more important, your precious time to do things for them when they most often would do absolutely NOTHING for you......but they do. A simple NO is good enough. No excuses and no explanations.
I was recently asked to knit a Nativity scene but in this instance, I had no hesitation in saying no. I told the person that the knitting would not have bothered me but sewing and stuffing countless tiny pieces would have driven me insane.