I am travelling from Bologna to Philadelphia on Feb. 28 and then back to Bologna from New York on May 4. Currently, the price is 458 Euro for British Airways. However, many online forums say that flights are usually cheaper on Sunday or Tuesday. Can anybody who travelled on this route tell if this price is reasonable or not? Are there good chances that I can get a lower price than this?
When studies show that flights are GENERALLY lower on Tuesday (I have not heard of Sunday), that determination is based on analyzing large quantities of data.
All that tells you is that on average prices on those days are lower and over the long run assuming you purchased tickets every day, you will get lower prices on those days.
However for ONE event, that is you buying your ONE ticket for ONE particular time, that data only gives you some probability. It does not do anything more than that.
In your case, with the kind of transatlantic flight route you are flying, unless you catch one of those smashing $100 for one way sales on flights like WOWAIR or Norwegian, you're not going to beat €458 by much. Plus those flights you typically have to pay more for baggage.
You have a quite decent deal. BA in the USA has free 24 hour cancellation. You can book today and check prices tomorrow which is a Sunday, if it's cheaper you can cancel the ticket you bought today and rebook for tomorrow at the cheaper price.In any case if you want to roll the dice, the price change between now and Tuesday wont likely be much because today till Tuesday are both just outside the two week window to departure.