If your choices are like 50/50 meaning you have no further details if who will likely to win that game then placing a bigger amount of money is a little bit risky. Gamble big amounts only if you are sure that a certain team has a big chances of winning.
Also, gamble only what you can afford to lose, as the popular saying goes.
For me, I will only gamble high amount if I know that I have high chance of winning.
It really depends on the person himself, his priorities, strategies and the likes.
It is better to spend small money if you are just looking for entertainment, because that will not give you much burden if you will lose all your money.