I work at a hostel in London, and we don't give room discounts when its all booked by the same party, generally. We give discounts on deposit, but hell you might as well ask. Also depends how long you're staying, most places will offer a weekly rate.
"All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity: but the dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible. This I did."
-T.E. Lawrence, Seven Pillars of Wisdom