Depending on the cost, normally on Tuesdays it's 30% off but that's only through SquareTrade.com; sometimes you might get luckier with more.
Also, don't insure it for the sale price. It's better to go for the going rate in case it can't be fixed. I got an amazing deal on a bluetooth speaker in January, paying $15 for it instead of the $100 that it normally sold for. I insured it for the full $100, but made sure to save documentation to justify the difference in the receipt and what I paid for.