Solo developer here selling a Windows desktop program for many years for $100 USD which includes one year free support (email only) and maintenance( free bug fixes and new versions). New customers are given a URL for downloading the licensed version(trial executable does not convert to licensed). After first year, annual support and maintenance is $20. License is sold as perpertual meaning it never expires. A few customers that purchased two or more years ago and have never purchased support needed to move software to new machine, which they can do using their installer. But if they no longer have their installer, they contact me and complain when told they they have to buy a new license. Support policy on my website is real clear about this: must be under a current maintenance contract to be able to download software. I have been lenient if their contract expired very recently, especially if it was their first year.
Older versions expire upon release of a new version and I do not offer installer for older versions because as a solo operator it would be too much to handle support for long forgotten bugs or other issues.
