Call your insurance agent. The type of car can make a difference in the cost of insurance. Dodge Neon's are cheap, but need repairs. Not bad for safety, but like most small cars less safe than bigger ones.
How cheap is cheap? The less you spend the more likely you'll need things like tires, brakes, exhaust systems etc. A check engine light on a cheap used car and make it "uncheap" real quick.
Old Honda's and Toyota's hold up good, but are not cheap compared to domestic brands. Stay away from VW and all European brands, they are expensive and need more frequent repairs.