Short answer
A marriage should not automatically be delayed merely because a family cannot afford an elaborate wedding.
Islamic Guidance
What Islam teaches
Islam encourages lawful marriage and moderation. The cost of a wedding should not be allowed to become an unnecessary barrier when the essential responsibilities can reasonably be managed.
Practical Guidance
What you can consider
Separate the essentials of marriage from optional celebration expenses. Plan according to actual means and avoid starting married life with unnecessary debt.
Sources
Qur'an 24:32; Qur'an 7:31.