Quick answer
Set budget according to customer economics, available audience, expected conversion rate and the amount of spend required to distinguish signal from noise. There is no universal Meta Ads budget.
A small budget should usually support a focused test rather than many audiences, objectives and creative variations at once.
What I would check first
I would check the conversion event, landing-page rate, lead quality and creative response before recommending more spend. If tracking is wrong, the budget is buying misleading data.
I would also inspect frequency and audience size. Rising frequency with weakening response can indicate that creative or audience breadth needs attention.
Decision framework
Start with the maximum sustainable CAC and work backwards through close rate, landing-page conversion and expected click costs. Then ask whether the budget can generate enough observations to make a decision.
If the business has a $500 customer acquisition ceiling and only one in five qualified leads becomes a customer, a $100 qualified lead target may be the upper planning boundary before gross margin and other costs are considered.
Implementation steps
Choose one business objective, one clear offer and a small set of creative concepts. Establish a baseline period, monitor qualified outcomes and change one major variable at a time.
Scale only when the measurement path and downstream economics are stable. When performance degrades, investigate creative fatigue, audience quality, landing-page friction and offer strength before assuming the answer is simply more targeting.
Common mistakes and current platform considerations
Do not divide a small budget across too many campaigns. Do not optimize to cheap engagement when the business needs revenue, and do not judge creative from a handful of impressions.
Meta's current delivery approach is heavily automated, so excessive manual segmentation can reduce learning opportunities. The better control points are the business objective, creative quality, conversion signals and economics.
Measurement and business implications
Use a funnel view: spend → impressions → clicks → leads/purchases → qualified outcomes → customers. Report both platform metrics and business metrics.
Use the Marketing Budget Calculator, Lead Value Calculator and Lead Funnel Calculator to stress-test the plan. Continue to the Meta beginner and placement guides for campaign execution.