How do I code a Dev. Product script that...?

How do I code a Developer Product script that gives you a certain amount of cash when you purchase the Developer Product? Example: Buy a Developer product for 10 R$ > Get 1,000 Cash

--Put this script in ServerScriptService.
--TIP: Press F9 during game for debugging.
local MarketplaceService = Game:GetService("MarketplaceService")

local currency = "Points" --Change

--Forces save to ensure no loss of data.
function SaveStats(player)
	player:SaveNumber(currency, player.leaderstats:FindFirstChild(currency).Value)
end

-- IDs (Change the numbers to match the IDs of your developer products. You may copy more.)
local productId01 = 000000
local productId02 = 000000
local productId03 = 000000
local productId04 = 000000

MarketplaceService.ProcessReceipt = function(receiptInfo)
	--local playerProductKey = "player_" .. receiptInfo.PlayerId .. "_Points"
	local Player = Game.Players:GetChildren()
	for i = 1, #Player do
		if Player[i].userId == receiptInfo.PlayerId then
			prodId = tonumber(receiptInfo.ProductId)
			local h = Instance.new("Hint", Player[i])
			--Purchase Points. Change the numbers however you desire.
			if prodId == productId01 then
				Player[i].leaderstats:FindFirstChild(currency).Value = Player[i].leaderstats:FindFirstChild(currency).Value + 25
			elseif prodId == productId02 then
				Player[i].leaderstats:FindFirstChild(currency).Value = Player[i].leaderstats:FindFirstChild(currency).Value + 120
			elseif prodId == productId03 then
				Player[i].leaderstats:FindFirstChild(currency).Value = Player[i].leaderstats:FindFirstChild(currency).Value + 375
			elseif prodId == productId04 then
				Player[i].leaderstats:FindFirstChild(currency).Value = Player[i].leaderstats:FindFirstChild(currency).Value + 1337
			else
				h.Text = "Something went wrong."
				Game:GetService("Debris"):AddItem(h, 4)
				print("Something went wrong.")
				wait(1)
			end
			SaveStats(Player[i])
			h.Text = "Your points have been saved! Thank you for purchasing!"
			Game:GetService("Debris"):AddItem(msg, 4)
		end
	end

	return Enum.ProductPurchaseDecision.PurchaseGranted
end