How much money should be saved before marrying?

There is no fixed amount in the Shariah; the only obligations are the mahr (dower) and the ability to provide maintenance (nafkah), while the cost of the reception depends on custom and choice.
Plan three parts: (1) marriage costs — mahr, registration fees, course and screening; (2) reception costs — walimah, hantaran (custom, not obligatory); (3) costs of starting life together — rent, deposit, basic furniture and emergency savings of at least 3–6 months' expenses. The Prophet ﷺ encouraged moderation; the best marriage is the easiest. Avoid large debts for the sake of the reception. Use the calculator and the mahr & hantaran guide to estimate.