I am having my mechanic replace the CV boot joint on my '00 grand cherokee. Is this a common problem? I also had to replace 3 injectors about 6 months ago, my water pump a little before that...

Am I going to continue to have problems with my Jeep? Should I hang onto it or try to cut my losses?

It all depends on how hard you drive it and how well you maintain the vehicle. Hang on to it but if you drive kind of hard, Look for a tougher vehicle. (not meant to be sarcastic)

The CV boots in the GC's, from what I've heard are not the greatest idea Jeep had, if your inclinde at all I have heard that you can swap out the CV axles for a set out of a XJ that has the "normal" universal-joint axles. Stronger and no boot to tear. Also, you can change those (CV) axles out yourself, with a couple of common tools. Email me at gtmud@earthlink.net. If intersted. As far as your injectors go, try running a bottle of MArvel Nystery Oil in your tank like every oil change. this will help clean and lubricate the injectors, hopefully cutting down on the replacement of further injectors.