Usually the short kit means only the plans and the basic shaped parts like ribs and formers and maybe molded parts like canopies and cowls are provided. The purchaser has to find out what materials like plane balsa sheets and strips, and plywood sheets and wire and wheels and other parts are needed and buy them himself.
Since most of the cutting is done, the short kit isn't especially any easier or more difficult than a complete kit, at least imho. The couple I built weren't any problem since I have a pretty good stock of wood and other materials at home. Since I bought a lot of that wood in bulk orders, there probably wasn't any major cost difference either.
If you have never built a kit before, you would probably be better off getting a complete kit or two to get used to what's involved, just to give you an idea how much material is involved beyound the preformed and precut parts.