I think you underestimate the seriousness of the market the BBC Micro was aimed at! The C64 was a very good games machine with good graphics and very clever sound for its time, but the real nerds, believe me, opted for BBC's if they could afford one.
Yes, it was expensive for sure, but it had capabilities way beyond almost anything of its day and was incredibly expandable, everything from second processors to different languages fitted to ROM expansion boards, the BBC was a superb programmers machine, in whatever language you fancied almost...
I had one (second hand, my parents were far from rich!) after a Spectrum, Electron and C64! - I preferred it to my later Atari 520ST and 1040(!) - I sold the Atari after a few years, but finally sold my beeb in 1990 and sorely wish now I'd kept it!
When you consider the ground breaking "Elite" game, I ended up with the enhanced second processor version which was absolutely stunning - for its day, you start to see how groundbreaking the BBC was, it had a very long life too, the first Model A was launched in December 1981, the last BBC Master Series went out of production in 1987 and was then followed by further -32bit- variants.
http://en.m.wikipedia.org/wiki/BBC_Micro Have a read, pay attention to the expand ability and programming languages that were available...