It really depends on the profiles of routes you're flying them (as always). With that said, I favour heavily the Caravelle. For a cost of 30M it carries on average 1077 PAX per day vs 1152 for the 732 @ 43M. Only a few less people for 2/3 of the price. Or, to put it another way, you can get 3 Caravelles for about the same price as 2 Boeings.
Obviously, Caravelle's limitation is range. So, again, it depends on the profile of each route.