When is it good to Sand/ Media blast your car?

I'm trying to figure if its worth it for me to think about spending 800-1200 dollars to strip my car completely and have it blasted and primered. That would mean all new window gaskets (Winshield being the hardest and most expensive to find) taking the K member and rear end out and that much more money out of my pocket. That would make it 800-1200 for the blast around 300 for both window gaskets not including the pass and drivers windows and tad more...What do you guys think? Up to which point in the car would you say...Im going to blast it...?