Some are actually crimped on and those should just pull off with pliers. some are permanently attached on at the factory and are not true crimp-ons, but more like soldered ends. Those need to be cut off. But I've only encountered a couple of those.
I've never had an lbs charge me for a single crimp-on. But it depends on the shop. I've had places throw in a whole new cable at no charge, and other places charge me almost $4 for a cable, and extra for the crimp.
I've never tried solder or glue, but they both sound like good ideas. Fraying is bad. Also, some cheap crimps will brake if you pinch them too hard, so pinch hard enough to get it on tight, but don't break the lil' thing either.