Q. (cont.) I know that it will only be approximate because the final cost will be based on the company's wants and needs. Where can I find such information? I'm trying to get an idea of the cost so I can get upper management buy-in.
A. While it's next to impossible to find comparison pricing on business software without contacting the vendors directly, here are some resources you may find helpful:
A fact sheet about the return on investment of T&E automation: http://www.frankrimermanconsulting.com/wp-content/uploads/2015/04/Concur-ROI-Factsheet.pdf
Capterra's resources and reviews on expense report software: http://www.capterra.com/expense-report-software/
A review of software by features, platforms, deployment methods (cloud or on-premise), and relative pricing: http://www.softwareadvice.com/accounting/expense-management-comparison/
PayStream's thorough review from 2015 of T&E solutions and pricing criteria, with information on whether pricing is structured per-user or per-transaction: http://www.ariett.com/sites/default/files/2015TravelandExpenseManagementReport.pdf
This forum encourages discussion of various T&E software and offers reviews and information about providers: https://www.g2crowd.com/categories/expense-management.
I was able to find one provider who mentioned that their per-transaction cost is typically less than $5.00 per report, considerably less than what Concur calculates manual per-report processing to be--$35.00. (Interplx, http://www.interplx.com/pricing/, https://www.concur.com/newsroom/article/are-your-t-e-costs-topping-the-charts). Depending on the quantity of expense reports you have, a per-transaction solution may be more economical, and while a cost savings that big may be unrealistic, it may get the attention of upper management to allow you to explore pricing further with specific vendors. (Just don't set their expectations unrealistically high!)
It's understandable that vendors don't publish their pricing because each company's needs are different, as you state. However, if during your research you do find vendors you'd like to know whether other members have experience with, let me know and I'll see what they say.