Repipes, water heaters, bathroom work and softeners are the opposite: considered purchases where someone gathers three quotes over a week or two, and the winner is frequently the one who explained the job best rather than the cheapest.
That is a content problem, not an advertising one. A page that sets out what a water heater replacement actually involves, what determines the price, how long it takes and what a homeowner should ask any plumber, will convert someone who read it and then rang you. Publishing a range rather than ‘call for pricing’ loses you the price shoppers and wins you the people who were worried about being taken advantage of.
Before spending on either half, what a lead is actually worth is the arithmetic worth doing — an emergency call and a repipe are not the same lead and should not carry the same acquisition cost.