has anyone used this option????

jet airways recently started online bidding for upgrades a few days before your flight....the upgrade amounts don't seem that attractive....for example, for my flight from dxb-del later this week the staring bid is about aed 900....if i add that to the amount i paid for my ticket then its just under aed 100 less than the amount i could have paid for a première ticket to begin with....

i'm probably not going to upgrade this time as the price doesn't seem right but for future reference i'm still curious what fare class the upgraded ticket would fall under....if its 'd' class then i won't get any miles from dl since that is not an eligible miles earning class as per their agreement with 9w....would be great to find out from someone who has used this feature....