Marriage in Islam does not require big amount of money. In fact it is recommended to keep the amount of Mahr (Dowry) affordable and not big amount.
Marriage in Islam can be a permanent marriage for those who can afford it and can be a temporary as well. In any case, Muslim must keep himself away from any sinful act whether he is married or not married. Those who want to get married to protect themselves from falling in sinful acts, will be helped by Allah as we read in many Quranic verses and authentic Hadeeths.
Wassalam.