Value don't changing

Hello developers!
I maked a rebirth button which add to cost value + 600 but it’s just changing text and nothing screenshot:


Debug - cost.

Code of Buy Rebirth:

local events = game:GetService("ReplicatedStorage").Events
local player = script.Parent.Parent.Parent.Parent.Parent.Parent.Parent

local amount = script.Parent.Amount.Value
local cost = script.Parent.Cost.Value

script.Parent.MouseButton1Click:Connect(function()
	script.Parent.Cost.Value += 500
	print(cost)
	events.Rebirths:Fire(player, amount, cost)	
end)

I can just a send to you a file with game?

You need to be using a remote event, not a bindable event. And this should be a local script if not already. Or more appropriately probably a remote function so you can get something back from the server confirming the player had enough money to change the text.

This creates a local copy of script.Parent.Cost.Value, so now:

cost = 600
script.Parent.Cost.Value = 600

You change it here: script.Parent.Cost.Value += 500
Now the values are:

cost = 600
script.Parent.Cost.Value = 1100

You should reference the value again, not the copy of what it used to be, like:
events.Rebirths:Fire(player, amount, script.Parent.Cost.Value)

Better yet, use a better reference:

local events = game:GetService("ReplicatedStorage").Events--be sure to wait for this child 
local player = script.Parent.Parent.Parent.Parent.Parent.Parent.Parent--this is a really poor reference by the way

local amount = script.Parent.Amount
local cost = script.Parent.Cost

script.Parent.MouseButton1Click:Connect(function()
	cost.Value += 500
	print(cost.Value)
	events.Rebirths:Fire(player, amount.Value, cost.Value)	
end)