If the stores would actually tell you the real "retail price" of sale items, I would be much more likely to buy things when they seem to be a good deal. But "10%" off usually just seems to mean that they jacked up the price 5-10% then marked off 10% of that. The last time I ever bought a BluRay from Borders, I had a 40% off one BluRay coupon, and they had Princess Bride at $40 (which seemed ridiculous, but it was inconceivable that I not buy it ASAP)... so I bought it for $24 and was happy as could be. Until I got home and saw the retail price everyplace else on the planet was $30 for exactly the same disk... and I could have got it for $18 on Amazon.
We were at Toys R Us a week ago when "ALL*" lego sets were on sale BOGO50% off... except two of of the four we tried to get of course. So we told them they could put back the Starwars sets and we would just get the last two... they rung up at $10 more than the price they had had on them just a couple days before when we were considering getting them. Turns out they raised the price of some (all?) of their legos ahead of the BOGO sale... we refused to pay the higher amount and a manager had to come authorize selling at their normal price... and 50% off of their normal price.
So yeah, I'm going to check prices at Toys R us and Borders... well, actually I've pretty much just stopped going to stores in the first place, but with my phone I can at least check if they are cheating me or not.