I don't think there is any comparison between a CA fresher package and a tob b school pass out mba fresher package due to following reason:-
Most of the top B schools including iim and fms requires professionals with experience of 3-5 years of industry. This is the reason why mostly engineers from iit or good engineering college having 3-4 years post qualification exp. get the entrance. Now suppose if you are earning 3-5 lacs p.a. already and then goes for further study investing 10-12 lacs then this is a prime responsibility of the institution to give you a package of at least 2-3 times higher than your previous one.
In my view all the MBA colleges don't do anything except polishing what you already have whereas CA provides you from basic to expert level knowledge of subjects (CPT to CA Final). This is the reason why it strats from passing 12th. and MBA only after Graduation.
Finally, I would say CA is a cap and MBA from Top B schools is a feather on that cap which really makes you stand among the most demanding professional.