I know very few people who have paid for excel specifically. everyone pays for MS office, albeit because it includes excel, but in an workplace setting the main thing you're paying for is outlook/exchange the fact that word/excel/powerpoint are bundled is a plus.
The main point I'm making is that no one has to go to their manager and justify paying for it. It's already bought and paid for, and because of its ubiquity most people have a pretty good idea of how to use it.
Even better, because some of those deals include MSDN, when Excel users grow beyond VBA, they just get VB.NET installed and keep doing AddOns in .NET.
Actually, everyone had to pay for that fork. Excel is a paid product, and isn't even included in the cost of Windows. It is, however, bundled with MS Office, which includes Word, which is even more of a must have at almost every single company/org.