Which is more preferable: completing university studies or marriage, especially since studies deplete finances and delay marriage?

If you can combine studying and marriage, it is better, as the Prophet, peace and blessings be upon him, said: "O young people, whoever among you can afford to marry, let him do so, for it helps him lower his gaze and guard his chastity. And whoever cannot afford it, let him fast, for it will be a shield for him." And the married person receives support and help from his Lord, as Allah Almighty says: "If they should be poor, Allah will enrich them from His bounty." If you cannot combine them, and your need for marriage is strong, and you fear falling into haram (unlawful acts), then prioritize marriage. Otherwise, there is no objection to prioritizing studies then marriage.