I think they don't have to get around it TTT. To use an example ::
Sofa ( purple or otherwise ) is on sale for £2000 for x number of weeks, Sells none or maybe only 1 or 2.
They then put said purple sofa into the "DFS Sale", at a much reasonable price of say, £1000. Many more sold as a result. Everybody is happy, including the local Consumer Affairs Dept.
Actually, some of the stuff in there is quite nice, if you can get past the bright red, or bright purple sofas. But its the size of most of the stuff that surprises me ! Some of those huge corner units wouldn't look out of place in the foyer of a big Hotel. How people get them into their houses without taking a wall down is beyond me.
Im sure their lawyers make sure they are doing nothing illegal but it makes a mockery of the regs. The law needs to be changed to make this type of manipulation impossible. Virtually all retailers are at it in one way or another. The real price is the one that you pay.