If the ball joints aren't loose/worn you have a little time, unfortunately without the protection of the boot, they'll get dirty and wear fast. At 100,000 miles your original struts/shocks are pretty much done, so are the cone or radius rod bushings. I'd probably bite the bullet and do all three at once. Usually the big bushings on the lower arm and the radius rod are OK. Be careful as some lower arms are aluminum, i.e. don't wail on them with your biggest hammer (or any hammer). Good luck.