We shifted our accounting to Tally beginning FY13-14. Instead of purchasing it outright, we chose the rental [subscription] mode, that costs INR 600 per month [including Tally.NET services and all sorts of updates/upgrades to the software]. The shift to Tally is expected to save us dozens of hours every week in accounting time [even after factoring in the time that will be spent to take regular backups of our data], and is also expected to enable us to have a more "real-time" view of our accounts/stock, as well as improve accuracy [by virtually eliminating arithmetic], among other benefits.
As a manager, I've decided to look at Tally as an employee that costs me only INR 600 per month. When I abstract Tally as an employee, the value that this software package gives me becomes visible immediately. An educated, qualified employee that works 24x7 without getting tired, takes no breaks, that creates and maintains a significant portion of my accounts and stock, that does correct arithmetic for me, that prepares my invoices and receipts, and so on, for only INR 600 per month. Where else will I get such a low-cost employee, one that is educated enough to do accounts books?
This abstraction is useful to me in order to decide if its price per month is justified against that value I receive.
It's a little bit funny to think of software as an employee, but a software that one purchases on a monthly subscription basis can always be abstracted as an employee - and I like the way I've made this comparison!