Change in price for Skip Stage gui dev product?

Hello. I'm currently trying to achieve a script that changes price depending on the stage someone is currently on. For example, is someone is on stage 1 and they click the skip stage gui, it goes to a dev product that costs 10 robux. However, if the user is on stage 5, it goes to a different dev product for 25.

My script:

MarketplaceService = Game:GetService("MarketplaceService")

MarketplaceService.ProcessReceipt = function(receiptInfo)
players = game.Players:GetPlayers()

currency = "Stage"

done = 0

for i=1,#players do
    if players[i].userId == receiptInfo.PlayerId then
        if receiptInfo.ProductId == 22277159 and done == 0 then
            done = 1
            players[i].leaderstats[currency].Value = players[i].leaderstats[currency].Value + 1
            players[i].Character.Humanoid.Health = 0
            done = 0
        end
    end
end
return Enum.ProductPurchaseDecision.PurchaseGranted 
end