Well I've clearly been spoiled by AA.

(Point of reference, AA's JFK-FCO o/w is $5)
AZ's €220 fee that you first mentioned is $322 at today's rate (not factoring in FOREX fees which my cc would charge). When I compared that to IB's $77 amount - to me the ~$245 difference was significant and enough to deter me from AZ.
Can understand you too!!!
Take a look at these then :-
BA on LHR - LAX = 525€ in taxes
BA on FCO (via LHR) -> LAX = 354€ in taxes
BA has always been steep on taxes (as you will read on other threads) but if you are flying in 5 (and you get the seats in J... And that is a big IF on the same flight...) flying AZ over BA will save you
200000 miles (FCO - LAX = 80000 MM rtn with AZ, 120000 BA miles with BA)
+
almost 1000$ in taxes (putting AZ at 220 and BA at 350 = 650€ difference)
American Carriers? No doubt
sk3, but how much would they charge for
LAX - FCO return?
Surely more than 100€?? (Italian taxes have to be paid..)