My priorities have shifted over the years. I always avoided basket cases, but when I was younger and had more energy than money, I bought somewhat rough projects and put lots of sweat equity into hunting down missing parts, rebuilding the mechanicals, then spending more money than I planned on bodywork and paint.
Now, I spend more money up front to buy complete, running, "ten footer" cars that look presentable, are mostly complete, and can be driven right away without having to completely disassemble them first. Even with those, there is still plenty to do fixing older "make do" repairs, replacing incorrect parts, and tidying up the loose ends.