I am in the same situation, any expert who can guide us?

You should be able to do it like any other A/B test. Set up a feature flag test: https://docs.growthbook.io/feature-flag-experiments. Then follow the instructions for your sdk: https://docs.growthbook.io/lib/ to check to see if the new price point feature is on and if so serve the new price.

If you are using something like Stripe or something where the price is fixed and hard to change programmatically per variations: You can advertise any price you like in the experiment variations, but actually charge everyone the lower price at checkout - usually people don’t complain about getting things cheaper.