Custom spreadsheet solutions which survive long after the developer has "left the scene", are often those which users accept because they discover it _ among other benefits _ makes their work quicker and easier to do. That is why the best person to develop such solutions tend to be one who works in that area, and is therefore familiar with the way the manual system operates. S/he would have an "insider's" perspective of the best way to introduce automation other users will readily adopt _ even as it solves the identified problem(s).
Variable Costs Control/Reduction was a strategy that worked extremely well for the company. Most memorable for me as a brewer, was the manner in which huge monetary savings/profit gains were made by successfully implementing variable cost reduction initiatives. For instance, a brewing ingredient switch was made to a more readily available local alternative which was many times cheaper, resulting in phenomenal savings and progressively increasing profit earnings even though the price of beer produced was not raised. This practice was routinely applied across the brewing and packaging processes in line with a well thought out plan.
This last point in my opinion is ONE major benefit you must seek to extract, if you choose to engage the services of a developer. S/he should be able to help you develop (in_house) expertise needed to maintain the application AFTER s/he is gone. If you fail to ensure this, all your cost_savings from using the application might end up being spent paying the developer to maintain the application over time in the future!
I believe the foregoing are compelling justifications for choosing Excel Visual Basic over Visual Basic.