I have done simular projects in my workplace. I optimized my own monthly reports, and I now do them for 15 minutes, instead of the 6 hours they took before automatization. Depending on the complexity of the macro, I can deliver much faster than 2 days.
I am Excel proficient user. I use macros for more than 2 years. I have successfully completed projects, saving 5-6 manhours per run (on a report, executed every day).
I do formatting macros, work with pivots, tables, file operations (splitting 1 sheet of data for different clients to separate files for all the clients, named with specific naming conventions), Outlook (meeting requests based on excel source, mailing distribution based on excel source).
My most complex project is generating metrics report for 60-70 accounts, using different tools with different tool logic (hence metrics logic for each), which serves the managerial team of my unit with all information they need on the monthly performance. Manually (with standart excel features, including formulas and pivots), reporting all metrics would take more than a manmonth, due to the poorly structured data in the tools, we now do it in a day.
I provide post-implementation support of the macros, if such is needed