How do I fix text says correct price but the price is half of it?

Hi so my upgradesGUI works but when i buy a item it shows the correct price I want but it removes half of the gems of the price it should be, how could i fix this?

Infochanger:

local moreRebirthsButton = script.Parent
local infoHolder = moreRebirthsButton.Parent.Parent.infoHolder
local price = infoHolder.Cost.price
local upgradeInfo = infoHolder.upgradeInfo
local upgradeName = infoHolder.upgradeName
local lastPrice2 = 250 --Last price

local Players = game:GetService("Players")
local player = Players.LocalPlayer
local upgradesFile = player:WaitForChild("Upgrades")

local maxRebirthButtons = 4

moreRebirthsButton.MouseButton1Up:Connect(function()
    local rebirthButtonsData = upgradesFile:WaitForChild("rebirthButtons")
    if rebirthButtonsData.Value < maxRebirthButtons then
        upgradeInfo.Text = "Purchasing this will give you a extra rebirth button!"
        upgradeName.Text = "Rebirth Buttons"
        price.Text = lastPrice2 .. " Gems" --Update Tex
        if infoHolder.Visible == false then
            infoHolder.Visible = true
        end
    else
        upgradeInfo.Text = "Purchasing this will give you a extra rebirth button!"
        upgradeName.Text = "Rebirth Buttons"
        price.Text = "Max"
        if infoHolder.Visible == false then
            infoHolder.Visible = true
        end
    end


    rebirthButtonsData.Changed:Connect(function()
        price.Text = lastPrice2 .. " Gems" --Update Tex
        lastPrice2 *= 2 --Set Last price to the new Price
        if rebirthButtonsData.Value >= maxRebirthButtons then
            price.Text = "Max"
        end
    end)
end)

upgradeSender:

local buyButton = script.Parent
local infoHolder = buyButton.Parent

local replicatedStorage = game:GetService("ReplicatedStorage")
local remoteEvents = replicatedStorage:WaitForChild("remoteEvents")
local buyUpgrade = remoteEvents:WaitForChild("buyUpgrade")

local Players = game:GetService("Players")
local player = Players.LocalPlayer
local upgrades = player:WaitForChild("Upgrades")
local leaderstats = player:WaitForChild("leaderstats")
local lastPrice = 500 --Last price
local lastPrice2 = 250

local maxRebirthButtons = 4
local maxClicksMultiplier = 5



buyButton.MouseButton1Up:Connect(function()
    local upgradeName = infoHolder:WaitForChild("upgradeName")
    local gems = leaderstats.Gems.Value

    if upgradeName.Text == "Rebirth Buttons" then
        local rebirthButtons = upgrades:WaitForChild("rebirthButtons").Value
        if rebirthButtons < maxRebirthButtons then
            lastPrice2 *= 2
            if gems >= lastPrice2 then
                buyUpgrade:FireServer("rebirthButtons",lastPrice2)
            end
        end
    elseif upgradeName.Text == "Clicks Multiplier"then
        local clicksMultiplier = upgrades:WaitForChild("ClicksMultiplier").Value
        if clicksMultiplier < maxClicksMultiplier then
            lastPrice *= 2 --Set Last price to the new Price
            if gems >= lastPrice then
                buyUpgrade:FireServer("clicksMultiplier",lastPrice)
            end
        end
    end
end)