A solid security system should last you at least five years, so don't settle for cheap gear that will be obsolete in six months. Focus on a reliable base station and wired or rechargeable outdoor cameras that don't trap you in a monthly subscription fee.
Tech brands usually release new models in the spring, which makes Black Friday the perfect time to grab the previous year’s version at a steep discount. You get the same performance for a fraction of the cost.
Remember that the 0% period is a deadline, not a gift. If you don't pay off the $450 balance within those 18 months, the card will start charging interest on whatever is left, which defeats the point of the plan.