Just looking at booking an outright award redemption in J but the surcharges are mental. It’ll cost me 145,000 miles plus almost 1000 euros on top for a return ticket. Last year, I managed the same route for 90,000 miles plus 250ish euros. 🤣

Because of this, I’m thinking of booking Y flex using cash and then upgrading for 39000 miles each way, of course depending on availabilty.

My question: if I was successful in upgrading from Y to J using this method, would EK also ask me for extra cash, be it due to taxes (premium cabin) or surcharges?