i don't know how much 705 sell in India. i'll just share some of my thought.
i listened to B&W 686, 685, 705, and 805s. (all price are December 2007 price)
686 ($450 pair): i think this speakers is only suitable for surround speaker or as a main speaker with a sub. the little mid/bass simply don't have any low frequency.
685 ($600) this is pretty much a full range already, if you are not talking about heavy bass. certainly enough for music listening.
705 ($1200 pair) my dealer is trying to get rid of all 700 series speakers. (they said the newer version will come in 2008) in my opinion, the 705 is BIG BIG improvement over 600 series. even the latest 600 series is NO comparison to the 5 year old 700 series. If your dealer is running a special on these, i think it would be a great buy.
805s ($2500 pair) this is another big improvement over 700 series. however, not as big as moving from 600 to 700 in my opinion. The 805s is more refine. if you listen to classic music, u will immidiately notice the difference. however, if you are watching movie, the difference is much smaller. (consider the big jump in price)
in the US, 800 series usually hold their value better than other speakers from B&W. if you upgrade later, u lose very little money on 800 series speakers.
300 sq.ft is quite small. are you saying you want to add a center channel and using only 3 speakers VS. 2 speakers? how about surround speakers?
actually, from my experience, in a small room, a good 2 channel speakers are very good for both movie and music. u will lose some surround sound but i don't think u miss much, though. I will get the best front L/R speakers i can afford and call it a day. If i need more speakers, i can slowly adding them later when budget allow.
