It can be hard to determine when you should still drop the thousands of dollars to get that repair done on your current car or if you should just replace it outright. However, the American Automobile Association (AAA) offers one rule of thumb when it comes to repair vs. replace cost decisions: if the cost associated with repairing a car approaches 50 percent of its current market value, then it's time to make serious thought about replacing it. However, you shouldn't just look at the estimated repair cost if you're evaluating whether to repair or replace your car — you must also consider other incidental costs, like the cost of bringing your car to the shop on a flat bed if it broke down somewhere distant or the total amount you'll have to pay on car rental while your current ride is in the shop. For example, if your car's estimated value is $10,000, and the total cost of the repair is $5,000, you should probably just save that money and get yourself an afordable and reliable used cars. If you know what to look for when buying second-hand, then you're not just getting a new-to-you vehicle, but also some peace of mind.