Why does my upgrade shop break in multiplayer?

Local script (Button)

local button = script.Parent
local plr = game.Players.LocalPlayer
local processEvent = workspace:WaitForChild("processEvent")
local cost
local Type
button.Activated:Connect(function()
	Type = "Jump"
	cost = 50
	local process = function()
		
		processEvent:FireServer(plr, cost, Type)
		print("plr, cost, type = " .. plr.Name,cost,Type)
	end
	
	local guiUpdate = function()
		
	end
	process()
end)

A part of the leaderstats script

local tf = true
	processEvent.OnServerEvent:Connect(function(plr, plr, cost, Type)
		print("receiced")
		if Type == "Jump"  and tf == true then
			tf = false
			print("receiced")
			if  game.Players:WaitForChild(plr.Name):WaitForChild("leaderstats"):WaitForChild("Coins").Value >= cost*game.Players:WaitForChild(plr.Name):WaitForChild("Folder"):WaitForChild("JumpLevel").Value then
				game.Players:WaitForChild(plr.Name):WaitForChild("leaderstats"):WaitForChild("Coins").Value = game.Players:WaitForChild(plr.Name):WaitForChild("leaderstats"):WaitForChild("Coins").Value - game.Players:WaitForChild(plr.Name):WaitForChild("Folder"):WaitForChild("JumpLevel").Value*cost
				game.Players:WaitForChild(plr.Name):WaitForChild("Folder"):WaitForChild("JumpLevel").Value = game.Players:WaitForChild(plr.Name):WaitForChild("Folder"):WaitForChild("JumpLevel").Value + 1
				game.Players:WaitForChild(plr.Name):WaitForChild("Folder"):WaitForChild("JumpPower").Value = 50 + 3 * game.Players:WaitForChild(plr.Name):WaitForChild("Folder"):WaitForChild("JumpLevel").Value
				workspace:WaitForChild(plr.Name).Humanoid.JumpPower = game.Players:WaitForChild(plr.Name):WaitForChild("Folder"):WaitForChild("JumpPower").Value 
			end
			tf = true
		else
			
		end
	end)
	

All the values get multiplied by the number of players (I think) but I'm not sure how to fix it.

I simply removed the part of the leaderstats script from the PlayerAdded function.