I can't change the int value even though the script knows what it is?

I've been working on an inventory system and when the player places an item down, the value in their inventory is supposed to decrease. However, this doesn't happen, and I'm not sure why.

The code I'm using:

wait(3)
local playername = script.Parent.Parent.PlayerNameTag.Value
local haveitem = game.Players:FindFirstChild(playername).Character.OwnedItems.BlueShrine.Value

if haveitem == 0 then
	script.Parent.Parent:Destroy()
end

if haveitem >= 1 then
	haveitem = (haveitem - 1)
end

The thing is... the script still knows what the value of BlueShrine is, as it still destroys the model when haveitem is 0. Does anybody know a solution? Am I making an obvious mistake?

You are missing the .Value

if haveitem.Value == 0 then
	    script.Parent.Parent:Destroy()
	end
	if haveitem.Value >= 1 then
	    haveitem.Value = haveitem .Value- 1
end