how do I make it so I can buy stuff in my game with in game money?

Here is the script I used to add money to my game. I want it so that if you buy something you get a tool.

local id = 1172399 


game.Players.PlayerAdded:Connect(function(player)
    local leaderstats = Instance.new("Folder",player)
    leaderstats.Name = "leaderstats"

    local Cash = Instance.new("StringValue",leaderstats)
    Cash.Name = "Cash"

    local doesOwn
    local success, message = pcall(function()
        doesOwn = game.MarketplaceService:UserOwnsGamePassAsync(player.UserId,id)
    end)
    if doesOwn then
        Cash.Value = "Infinite"
        print(player.Name.." owns the gamepass")
        game.ReplicatedStorage.Notifications:FireClient(player,"You own the infinite money gamepass!")
    else
        print(player.Name.." does not own the gamepass")
        game.ReplicatedStorage.Notifications:FireClient(player,"You do not own the infinite money gamepass.")
        Cash.Value = 0
        while wait() do
            wait(10)
            Cash.Value = Cash.Value + 25
        end
    end
end)