so, if i get updraded basically depends on whether any business class seats are still available on the day that they would process a possible upgrade, correct?

well, the difference between the Y/B fare and a discounted fare is actually not that much if you buy from the airline directly. so, thats good. but the thing is that i could go with a differentl airline altogether and get a similar itinerary for half or 2/3 of the price... so, i guess, it is a gamble...

thanks a lot though!