Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
If the groom is poor, the marriage is valid as long as both spouses willingly agreed to conclude the marriage contract with full knowledge of their financial status.
Responding to your question, Prof. Dr. Monzer Kahf, a prominent Muslim economist and counselor, stated,
We should also point out that young men and women should seek marriage with equal partners socially and financially. Equality will help the spouses live a happy life based on mutual respect, love and understanding.
Yes, the marriage is valid as long as the bride agrees to help her groom voluntarily. This happens very often nowadays. The wife’s spending should be promised willingly and she does not make a condition that she is doing so on a loan basis to her husband.
Additionally, her spending may be cut at any time on her own will and decision. In such a case, the husband, poor as he may be, is required to provide for the family and she can take him to court for it.
Allah almighty knows best.