We are heading to Italy in January, flying into Florence.

Using the exact same flights, Air France (or Air France flight booked on Expedia) will sell me the ticket at $788 round trip.

Expedia, again, using the exact same flights (Delta to CDG, and Air France or its code share to Florence) booking it as a combination of Delta and Air France codeshare flight numbers , will sell me the ticket for $806.

Delta.com?
They'll sell me seats on the exact same flights for $1043.

Absolutely ridiculous.

Much as I'd like to give Delta the money, there's just no way I'm paying that kind of premium.