Where else can I find it?

These days, they are releasing collections of old games. I've seen Heroes 1, 2, and 3 for sale at least a couple of times. So, M&M might be available too, or will be soon!))
Also, try searching for something like "download old games" in a search engine. For example, there's a lot of stuff here: http://www.old-games.ru/catalog/