A split test fits when two reasonable versions compete and the page gets enough visitors to tell them apart. HubSpot's page A/B test, available on Content Hub Professional and Enterprise, serves two versions at one URL and sends half the visitors to each. HubSpot recommends changing one variable at a time. That advice suits the pricing example, because a variation that moved the table and rewrote the plan names would leave you unable to say which change mattered.
How long the test needs depends on a few inputs, and Optimizely's guide to experiment length lists them: the page's current conversion rate, the smallest difference you care to detect, the significance setting, the weekly visitors and the number of variations. The useful consequence is that a small expected difference needs far more data than a large one. A calendar deadline doesn't add evidence, so a test stopped because the month ended has only told you what it had collected by then.
Testing tools also don't all decide the same way. Optimizely's own statistics engine evaluates results continuously and doesn't need a sample size fixed in advance, and the same guide warns that fixed-sample calculators estimate its run time poorly. So write the decision rule before launch, and write it for the tool you're using. In HubSpot, a person picks the winning version and the other becomes a draft. The tool carries out the choice, and the evidence behind it is the team's responsibility.
This is also where the sprint and the test come apart. Lean Labs runs its improvement work in 30-day sprints, and a sprint is a schedule for the team's work. The test ends when its rule says to stop, which can be after the sprint closes and can be without a clear winner. Let it keep running, and plan the next sprint's work away from the tested page where you can.