How to make a ShopGui that you could purchase with currency?

So first of all, you need to make a leaderstat folder in your player. You do this by putting this script into your workspace.

game.Players.PlayerAdded:connect(function(player)
	local leaderstat = Instance.new("Folder",player)
	leaderstat.Name = "leaderstats"
	local Coins = Instance.new("IntValue",leaderstat) -- change "Coins" to whatever you want
	Coins.Name = "Coins" -- Stat name -- change "Coins" to whatever you want
	Coins.Value = 10 -- Starting coins  -- change "Coins" to whatever you want
end)

Then after that, you need to go to the toolbox and get a speed coil or item you're trying to buy.

Making the Gui should be simple enough: Add a ScreenGui in the StarterGui in explorer. There, you put a button for opening/ closing the shop. You will also need a frame to open. In the frame you'll need a TextButton. The Button for Opening/Closing the shop should have a script looking like this:

local Button = script.Parent
local Frame = script.Parent.Parent.Frame

Frame.Visible = false
Button.MouseButton1Click:Connect(function()
	Frame.Visible = not Frame.Visible
end)

When you design your shop inside the frame, you need to insert a StringValue, IntValue and a localscript in the Textbutton. The IntValue should be renamed to "Price" and StringValue to the item you want to sell(in this case it is "SpeedCoil"). I will write the localscript later since I have no time right now... But I'm sure someone can help you.

UPDATE: I have made a localscript specifically for the Speed Coil... Just put this script inside the item Button.

----------[Scripted by Ghost40Z]

script.Parent.MouseButton1Click:Connect(function(player)
	local Button = script.Parent
	local Price = Button.Price
	local player = game.Players.LocalPlayer
	local leaderstat = game.Players.LocalPlayer.leaderstats
	if leaderstat.Money.Value >= Price.Value then
		leaderstat.Money.Value = leaderstat.Money.Value - Price.Value
		local ClonedCoil = game.ReplicatedStorage["Speed Coil"]:Clone()
		ClonedCoil.Parent = player.Backpack
	else
		print("Player doesn't have enough money...")
	end
end)