I think you've gotten it mixed up a bit or I unintentionally confused you (apologies if that's the case
)
What I'm saying is:
The quote: "relative to your fare class" means it assigns it based on time stamp within the same fare class.
Fare Class is meaning Anytime Fare, WGA Fare, Senior Fare, etc.
So for example let's say you have two people who purchased WGA Fare--one person purchased EBCI 6 months ahead of the flight but the other purchased it 5 months ahead of the flight. The person who purchased it 6 months in advanced is assigned the EBCI before the person who purchased it 5 months ahead because the timestamp for the purchase of EBCI
within the same fare class is earlier.
However, Anytime fare has higher priority in assignment of Boarding passes than WGA fares. Therefore if you purchased WGA Fare with EBCI 6months out but someone else purchased Anytime Fare let's say 5 months out as well as EBCI at the same time they will have higher priority than you who only purchased WGA fare.
Senior Fares are fully refundable and based on the situation the PP had I would guess Southwest is placing higher priority in terms of assigning Boarding positions to the passenger with the Senior Fare.
As far as price of the ticket----that sure isn't helping my husband out lol. His flights average $500-$700 RT to get from the LA area to KC every two weeks. His tickets however are purchased 2-3 weeks out;mostly 2 weeks out. He's been getting EBCI at that time (his company pays for the plane ticket and the EBCI). He has gotten mid to high A's and into the B's. Today his flight to Phoenix to catch his connection he was A60 and from Phoenix to LAX he was A43. His previous flight was booked further in advance because it was 4th of July weekend. From KC to LAX non-stop this time on 7/7 he was low B's but I don't remember the exact number. Every flight is different numbers; he purchases roughly the same interval as far as about 2 weeks ahead but each flight is comprised of different passengers.