attempt to index upvalue?

So simple shop GUI and this is the purchase button. Here is what it says when I try to click purchase: Players.Player1.PlayerGui.Shop.infBack.Buy.LocalScript:8: attempt to index upvalue 'wep' (a nil value)

So yeah and here is the code:

local but = script.Parent
local gun = but.Parent.Weapon.Value
local wep = game.ReplicatedStorage.Weps:FindFirstChild(gun)
local player = game.Players.LocalPlayer
local pack = player.Backpack

but.MouseButton1Click:connect(function()
    wep:Clone(pack)
end)

Weapon is a StringValue. I tried changing the variable gun to just but.Parent.Weapon and no .Value but that also does not work.

Now i'm certain that the gun is in the folder(weps) in replicated storage I could see it when I clicked purchase so i'm not sure what i'm doing wrong here. Any help is appreciated :)