My understanding is that paying is completely different from approval. You may only predict when you will receive the Green card after it has been approved. Once approval you should receive the card within 1-3 weeks. Payment usually aligns with time of application for the green card, the next approval step is determined by your Priority date and how much backlog is at your specific processing centre. Mine took almost 8 month to be approved. Hope that helps.

no relationship between payment and when is green card received.

im asking for after a whole i-130 approval pettition and consulate visa approval. like once the person is already in the US and the fee is the only thing that has to be payed .?