One such avenue open to those who cannot afford to marry a woman in Nikah...
and besides these, it is lawful for you to marry other women if you pay them their dowry, maintain chastity and do not commit indecency. So those (women) whom you marry for an appointed time, you must give them their agreed upon dowries.
There is no harm if you reach an understanding among yourselves about the dowry, Allah (SwT) is All-Knowing and All-Wise." (Surah 4, Verse 24) This is a commandment from Allah (SwT) which was not only mentioned in the Quran, but which He commanded his last and greatest Prophet (S) to convey to the Ummah, which can never be made forbidden by anyone as that which Muhammad (S) has made halal is halal until the Day of Judgement and that which he has made haram will remain haram until the Day of Judgement.
Not only does our dress act as a beautification for ourselves, but it also covers any defects that we may have on our physical body - thus, if a person has a scar or burn mark on his body, the clothing will cover this from others around him and thus, they would not know that he has such a physical 'defect'. The husband and wife are to play the same role in relation to one another.
If the wife has spiritual defects or lacks something in her character, then the husband must cover these up and not expose her shortcomings to others. The wife too, must cover up and hide her husband's deficiencies and weaknesses and protect her mate.