I was just in B&Q (Reading) and they appear to have loads of lighting on clearance. I picked up two lamps originally marked £15.98 each for £2 and a shade originally priced at £14.98 for £5.
There were table lamps, chandeliers, shades, wall lamps all marked down (most tags were either £2 or £5) and they were all in pristine condition - none of that battered rubbish you normally find in clearance. There was also a lamp orginally £31.49 marked down to £5 but I have nowhere to put it so left it!
I don't know if it is store specific or whether it's a national clearance.