A new battery costs around 70 to 100 (depends on quality) Plus tax.
It guarantees working for at least 4 fours. Mine works for eight years (I paid 115 CAD).
Also, if you have a booster cable (costs around 40), then you can ask your neighbour to jump start your car. You can ask any driver, and give them 20 bugs, they are willing to jump start your car.