Instrinsic value of goods on sale - what is it?

Hello, I’d like to purchase an item from the US and I’m trying to estimate the import charges that I would be liable for if I go ahead with the order. The item is on clearance. Its full price is USD 249.99, but it is now sold on discount for USD 99.99. In addition to this, I have a discount code which will bring the cost down by 30% to USD 69.99. Which of these prices will HMRC use to estimate if the goods are above or below the £135 threshold, and to determine customs duties? The price I will pay (i.e. USD 69.99) or the original price of the item before it went into clearance (USD 249.99). Note that the invoice will show these values, i.e. it will state I saved USD 180. Thanks

Hi,
The guidance below covers how to work out the customs value for Customs Duty, import VAT and trade statistics if you are an importer or clearing agent: 
Working out the customs value of your imported goods
There are several valuation methods, Method 1, transaction value, and covers discounts. You can see the guidance here:
Valuing imported goods using Method 1 (transaction value)
Thank you.