Cheaper phones = more volume sales?
Are you sure? That's the sole reason?
Symbian was open sourced like Android. Within two years, Android surpassed it. Symbian never had the marketshare penetration the way Android has now.
Research In Motion had multiple phones too from different price points. Android destroyed BlackBerry too within two years.
Windows Mobile and Palm OS/webOS never had the same marketshare.
Windows Phone offers cheap phones. The Lumia 520, 530,635,and 640 were all phones that can bought for under $50. Why didn't it take off?
Samsung really did help Android become popular. They overtook Nokia to be the world's most popular phone manufacturer by 2012. Maybe that is also a good reason but not only reason why. Educate yourselves with mobile history. The real power comes from the mind. Not the platforms you or me might prefer.
Just because you prefer iOS doesn't mean if we use Android is because we can't afford iPhones. Listen, I tinkered with Android, iOS, WP, webOS, BlackBerry OS, and Symbian S60. I prefer Android the most. It simply is more customizable out of the box. More PC to me. Both WP and iOS might be smoother, but boredom sinks in faster.
I will get bored of iOS within days because I hate how it doesn't have an app drawer, can't hide apps, can't change the icons, can't change the animation, can't use gesture shortcuts. Feels like Communism to me. Different plug to charge it. Proprietary everywhere. No micro-sd slot. You have to keep waiting if Apple will ever add an "old" feature that Android had for years.
It's not even a contest in sales. 80% is a landslide victory over multiple OSes that had different price points and OEM's, and whatever excuses you keep using. No different then when Windows spanked Macs in the desktop OS. Give credit where credit is due. Android kicked everyone's azz. Apple might take home the mobile profits but that won't last forever if they can no longer grow their installed base.
Aim higher, kids.