I think some governments in several countries have provided a fixed amount of money used for these political campaigns. But, sometimes the idea that they should further lower the costs to prioritize other more demanding needs for the people and the building of the country should be taken into consideration. So, yes, perhaps with the help of the law, costs for these extravagant campaigns could be lowered to a more realistic number.
I assume that based on the idea that without a limit the elections become a "race" of who spents more money in the campaigns. In countries like Brazil for example those expenses can be really high (like 4million dollars for one single cadidate), not to mention that this money should be spent for the welfare of the society, not in some auto advertising. In my opinion political campaigning is silly and disrespectful to all citzens who pays taxes, it should at least have a roof.