In my experience, even lower end Campy groupsets can be rebuilt. As far as it being "pointless" to be buy anything less than Chorus, it really depends on what you can/cannot live without. Chorus on up offers "ultrashift" which allows you to make more sweeping upshifts and downshifts with just a single action of the shifter. I had it on a lower end Campy group circa 2006, and it was nice--but if you don't do a ton of climbing and/or don't race, it's not crucial in my opinion. I don't have it on my 2009 Centaur group, and while I sometimes miss the ease of it when I'm getting ready to descend, it's not like I can't ride my bike without it. Even mid-range and lower end Campy components are very nice, and the shifting is smooth and precise. So, for anyone looking at Campy, I'd suggest just going with what your budget allows. It is so easy to get seduced by the higher end stuff because it's gorgeous and performs extremely well. But in my opinion, the average recreational cyclist will be satisfied with the mid-range, and even lower end, components as well. But there are a lot of Campy snobs out there, so I'm now going to duck and run!
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher