I am a 1K and recently took a flight from EWR-MSP on United Express. All economy+ seats (really just exit row on the Emb145RJ) were taken so I was in a economy seat. After boarding completed, I noticed an open seat at the exit window. As the door was closing I asked the FA if I can move to the seat. She said even as a Premier member they had a new policy that required payment ($125) for that seat. I was shocked and explained that made no sense. She ultimately relented but was still adamant that she was only doing me a favour. Anyone experienced this with United Express?