Depends though, how long can you hold off the allies from threatening Italy from the sea if you purchase boats? Honestly I wouldn’t buy a fig and a carrier though, if your going that route go all the way and let the Germans and Japaneses lands planes on your carrier for you.
Look at it this way, by the end of J3 there could be a fleet of 2 loaded carriers, 2 cruisers, a battleship, and a destroyer or two. That is 11 hits, 5 @ 4, 2 @ 3, and 1 @ 2. I doubt the allies have the air power on turn 3 to take that out, and if they do they don’t have many trannies to push afterward. The allies also must be careful at that point of splitting there fleet and Italy suicide into the US’s boats if the UK moves her boats. Can be very effective against an all out push from the allies on Europe.