Budget for consulting Firm:

I have already been in this business since1999 ... and from my experience, I can tell you that the answer differs from case to case. This depends on several factors including

1. Number of customers / markets / industry sectors you are covering
2. The geographical extent (coverage) you have  .. described in number of locations, number of employees per location, and possibly number of customers per location
3. Number of offerings you have ... you mentioned two of them (customized marketing pplans and product launches) ... but you need to take into account all your offerings
4. The balance between your "push" sales activities and your "pull" sales activities. What you do in proactive mode, and what you do in  reactive mode ...
5. Your business model and its reliance on resellers/distributors/channels/associates/partners and possibly other external entities/individuals

There could be other things which determine your size and diversity, reflecting on the specifics, details, functionalty and features of the budgeting system  that is best for you.   last thing, I try to keep tihings simple, and if I can accommodate my needs using Excel sheets, then why should I opt for complex, expensive and demanding software packages ??