How To Make It Save The Cost Of An Item And Save IntValues?

https://cdn.discordapp.com/attachments/447457287376994304/494905176889753610/unknown.png this is the folders

this is the script for the shop

button = game.StarterGui.Shop.Frame.ImageButton
player = game.Players.LocalPlayer
cost = game.ReplicatedStorage.StatFile.LocalPlayer.statnumbers.cost1.Value
add = 1

button.MouseButton1Down:connect(function()
    if player.leaderstats.Money.Value >= cost then
        player.leaderstats.Money.Value = player.leaderstats.Money.Value - cost
        player.leaderstats.MPS.Value = player.leaderstats.MPS.Value + add
        cost = cost + 50
    end
end)


while true do
    wait(0.01)
    script.Parent.Text = "Cost: "..cost
end

also i want it to save the cost the intvalue but im not sure if i have done the datastore correctly

local DS = game:GetService("DataStoreService"):GetDataStore("test")
local StatFile = game:GetService("ReplicatedStorage"):WaitForChild("StatFile")

game.Players.PlayerAdded:connect(function(player)
    local playerFolder = Instance.new("Folder", StatFile)
    playerFolder.Name = player.Name

    local statnumbers = Instance.new("Folder", playerFolder)
    statnumbers.Name = "statnumbers"

    local cost1 = Instance.new("IntValue", statnumbers)
    cost1.Name = "cost1"

    local add1 = Instance.new("IntValue", statnumbers)
    add1.Name = "add1"

    local thing = Instance.new("StringValue", statnumbers)
    thing.Name = "thing"

    local str = Instance.new("StringValue", statnumbers)
    str.Name = 'str'
    str.Value = 'thisIsAString'

    local savedStuff = DS:GetAsync(player.userId)

    if savedStuff then
        print('data takes up '..game:GetService("HttpService"):JSONEncode(savedStuff):len()..'/260000')
        for i,v in pairs(savedStuff)do
            print(i,v)
            if i % 2 == 0 then
                StatFile[player.Name].statnumbers:FindFirstChild(savedStuff[i - 1]).Value = v

            end
        end
    end
end)

local function saveValues(player)
    local savedData = {}
    for i,v in pairs(StatFile[player.Name].statnumbers:GetChildren()) do 
        savedData[#savedData + 1] = v.Name
        savedData[#savedData + 1] = v.Value
    end
    DS:SetAsync(player.userId, savedData)
end

game:BlindToClose(function()
    for i, player in pairs(game.Players:GetPlayers()) do
        saveValues(player)
    end
end)

game.Players.PlayerRemoving:connect(function(player)
    saveValues(player)
end)