I was thrilled to see that JetBlue is adding two nonstop flights with mint BOS-LAS starting in January, I fly this route twice a year. I checked prices and they are $849 on the way there and close to $1200 on the way back. I figured there must be high demand given that the rates 'start at' $599 each way, but every seat is available, for some flights in April 2018. So, few questions:

1. Are there not necessarily ANY $599 mint seats available on every route?

2. could prices come DOWN between now and then or does jetblue's pricing not work that way?

3. does jetblue have options for buying an economy ticket and then paying to upgrade to mint at some rate lower than just straight up buying mint seats?