The verdict
For most lean B2B founders, Leadpages is the call. It is cheaper at every tier, it has a free publishing layer so you can ship before you spend, and its CRO plans (Grow at 49 USD/mo) undercut Unbounce's entry point while still giving you A/B testing and AI routing. You get to a live, tested page with the smallest possible commitment.
Unbounce earns its higher price only when landing pages are the engine of a paid-acquisition machine. If you are pushing meaningful ad budget and will lean on Smart Traffic routing and serious experimentation, the 29 USD/mo entry (and the steeper Experiment/Optimize tiers above it) buys depth a founder running one or two pages will not touch. Below that bar, you are paying for headroom you do not use.
Neither tool does quizzes or calculators, so if interactive lead-gen is your wedge, both are the wrong starting point.