A model train set is built using a scale of 1:100. If the model of a train car is 4 centimeters long, how long is the actual train car in meters? Additionally, if the model train car costs $50 and this price is 20% of the total cost of the entire model train set, what is the total cost of the model train set? Let's think step by step and output the final answer within \boxed{}.
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