Hello all,

I have never upgraded with miles before and was wanting to book a full-fare main cabin (Y class) and upgrade to business class by using 25,000 miles. When my confirmation email came out, they ticketed me for an O class which is discount economy. I reached out to AA and they told me my main cabin economy rt of $998 is the cheapest main cabin fare and to upgrade me to an Y I would have needed to pay $5425 RT. This sounded ridiculous to me since premium economy RT was $2779 and RT business class seats were $4316. She said what I am looking at are the cheapest available AA seats and Y class cannot be booked online and I have to call someone to make that booking.
Can someone tell me if this makes sense and if they run into this issue before that to upgrade to business class, I would first have to spend $5425 for a Y class economy seat and then spend 25,000 miles to upgrade to business class seat or else just buy the business class seat for $4316 and save money.