From memory (and I'm thinking back about 10 years) it didn't cost any extra to join roadside. Although back then I think you only had to join for 1 year rather than 2. I'm pretty sure it was really easy and straight forward though

Or I guess you could see if you have any kind neighbours with jumper cables that want to help you jump start the car? I'm not sure if that's something most people know how to do. My dad's a mechanic so I guess he made sure I knew how to do it.