IMO the only reason to buy an A+ is if you are going to be using these commercially at scale, where the minimal price and power consumption differences are going to add up.
For example, let's say you have a company which does school scoreboards, you might install 3x a month, 36/year. You can do a custom Pi solution for $35 (+software), or buy the commercial solution for $150+/board.
For that type of operation you likely wouldn't make your money back having someone else produce a bespoke board for your 36/year installations. Even at three times that number it likely wouldn't be cost effective.
You see this a lot in niche installations. Up until somewhat recently many POS terminals in small stores were just standard desktop PCs wrapped in a custom case and with some custom software (sometimes written in VB6(!)).
Even in larger stores they ran Windows. I used to work for a large supermarket in the UK and the checkouts even now run on Windows NT and Windows XP with a custom UI. There are special versions of Windows for this sort of thing: