Re: Oh, yeah...
Give them the money
You mean the $50,000 that you might have to pay to have a consultant come in and rewrite some vital application code so that it runs on Windows 10? If it ain't broke, don't fix it.
(Hypothetically assume that it was an old old application when it was installed on Windows 7 ... but it worked AOK then and now. Also assume that somewhere down the years, the source code and/or the organisation that wrote the original have disappeared. And that they have actually tried reinstalling it on Windows 10 without success. )