There isn’t a definitive answer to the question, “which company is the cheapest?” Some companies are cheaper than others, plain and simple, but individual details of your driving profile can affect which companies offer you the cheapest rates. For example, while Nationwide wasn’t the cheapest for a driver with a clean record, it was the relatively cheap for a driver following an at-fault accident. The best way to find cheap car insurance is to compare as many companies as possible using your driving profile.
Collision coverage has a deductible, which is the amount you pay before your coverage helps pay for your claim. You can typically choose the amount of your deductible when you buy coverage. So, if you choose a $1,000 deductible and your car is later damaged in a covered accident, you'd have to pay $1,000 toward repair costs. Your collision coverage would help pay the rest, up to your coverage limit.