I believe using either of these two applications should not pose any problems for implementing your spreadsheet automation ideas. This is because both have always been "friendly", towards making it easy for users to get more functionality out of them by way of custom programming.
I believe the foregoing are compelling justifications for choosing Excel Visual Basic over Visual Basic.
The savings _ from using your "in house" expertise _ in terms of money and man_hours alone, will quickly justify the investment you make in "developing the needed skills" _ especially, when you compare what you spend with the cost of purchasing a commercial software application _ or even engaging the services of an Excel VB developer.
The intelligent use of spreadsheets, combined with the application of the 80ᚼ rule will help to achieve the foregoing and more. One does not need any expert to start doing these things today. Just take the decision to start keeping daily, accurate records and commit to analysing them. You'll be surprised to find that you will soon become much more aware of how you're doing and what aspects of your business you should focus on more to get better returns for your efforts _ and you will be able to confidently supply verifiable/authentic financial data to back up any claims you make about your business performance to bankers or prospective investors.