A boosted Page post can be enough if it brings in the conversations you actually want. If the goal is leads rather than visible engagement, compare it with an Ads Manager campaign on that outcome—not on likes or reach.
A useful test is to take one offer, such as a consultation, and write down what counts as a qualified message before spending anything. For example: the person asks about the service, is in the area served, and gives a plausible timeframe. Then compare a boost of the Page post with an Ads Manager campaign using the same offer and a similar message destination. Keep the creative, audience, budget, and dates as comparable as practical. If both run at once, use separate audience segments where possible so they are not competing for the same people.
Check the boost’s selected goal in the Page’s ad controls and the campaign objective and delivery status in Ads Manager before interpreting the results. Those setups may optimize for different actions. A boost with an engagement goal that collects likes but few qualified messages has not necessarily failed at its objective; it has failed the business outcome in this test.
Count qualified messages and cost per qualified message for each setup, using the same qualification rule. If a boost delivers enough of those conversations at an acceptable cost, the extra campaign setup may add little. If it does not, the campaign gives you a separate way to test delivery against the intended action.
What downstream outcome do you use to decide when a boost is sufficient?