A learned a lot from your comments on the scissor sharpening post:
Rosa said that Portugal has these roving sharpeners, or amolador de tesouras, who have bike-powered sharpening tools and play a unique tune on a flute to announce their arrival. Doesn’t that make you so happy?
Sarah wrote that folding some aluminum foil a couple times and cutting into it a bunch will sharpen your blades in a pinch.
And it appears that the going rate for plain (non-pinking) sewing shears is around $7 in the U.S., so don’t pay any more than that!