Open Jaw or?

It's really hard to say without knowing the destinations. Is there some reason to not say where you are going?

Sorry. I haven't cleared the trip with my whole family, yet, and I was afraid of one of them reading it! Starting in Seattle. Spending a few days in Rome and then the rest of the trip in Germany (Frankfurt for airport). Rome seems to be a pricey addition for open-jaw pricing- and then taking the train from Rome to Bavaria (our destination) isn't cheap, either. It almost seems cheaper to fly round-trip to Frankfurt and then add round-trip tickets between Frankfurt and Rome to the mix via maybe a Lufthansa value airline.

Open jaw, if reasonably priced. If you can't get back to Destination B in time for the trip home, you would be on hook for the cost of getting home (since you would be a no-show). The open jaw has less time in transit, which means more time doing stuff and less stress.

One of the things that I have found in booking an open jaw ticket is to use the same airline throughout the trip. Going with 1 airline for the home to Europe leg and a different airline for the Europe tohome leg can be (though not always) quite expensive because you are essentially booking 2 one-way tickets. By using the same airline, it becomes a round trip ticket for the airline, even if you fly into 1 city and out another. It's not always possible to do but does help with the cost.

It's a cost-time thing. Get a price for both open jaw and round trip from the same city. Then add up ground travel costs under both options. That tells you which is more cost effective. If open jaw is cheaper, do it. If round trip is cheaper. you have to decide if the extra travel time is worth the savings. Sometimes a loop beginning and ending at the same place is very cost and time effective and doesn't involve any extra travel time. So how it works out has a lot to do with route.

Cate - Sorry for not a clear cut answer but, it just depends.... As other posters have mentioned, you need to add up the cost of each and then decide what is the best option. Quite often we fly round trip to London and purchase other tickets to our European destinations. Sometimes booking all the flights together on one ticket comes out cheaper. This year the cheapest and shortest flights were into Istanbul and out of London - purchasing a separate ticket from Bodrum with a stopover in back in Istanbul for a couple of days and then on to London. One note on Frankfurt - have you priced tickets out of that area to your other destinations yet? Every time I have, the prices have been really high and it has never worked out even with a inexpensive transatlantic flight to Frankfurt. As for the cost of flights within Europe, it's easy to just add the baggage fees. The larger airlines - British Airways, Lufthansa, Turkish Air, Aegean usually don't charge for a 1st checked bag. easyJet and others do charge, but it's usually reasonable.

We use open jaw tickets for nearly every trip. Have never found them to be more expensive and sometimes cheaper. Even if different airlines are involved, it is not, as suggested, treated as one way tickets. Right now we are looking at a last minute trip in mid September. We are going into Barcelona from Denver, then return to New York from Athens, and finally back to Denver from New York. All on one booking for about $1200. As long as it is a RT it doesn't matter how many legs you put into the flight. Each legs adds a bit but the total is far less than if arranging individual flights. Unless you are doing a circle route, it never makes any economic sense to return to your starting point. The best proof will be for you to use one of the search engines and price out the various patterns.

The dicey proposition about Option B is if one of the airline carriers changes your flight(s). We had a situation a few years ago where we flew round trip into Frankfurt on American Airlines and had tickets on an unrelated airline (Croatia Airlines) to get us into/out of Croatia, the kind of situation you are considering. We had padded the layovers in Frankfurt several hours each way in the event a flight was late. All was roses until we received an email from American Airlines saying they had changed our return flight home from Frankfurt - to two days earlier! Of course we immediately called them to find they had outright canceled our return flight to Chicago and were re-booking everyone and sorry, take the change or leave it. Much back and forth ensued, fur flew, and in the end, we managed to get on a flight leaving the day or two (can't remember exactly) after our original flight. Because we didn't want to overnight in Frankfurt we ended up changing our Croatia Airlines flight but we naturally had to pay the change fee and difference in flight costs. So. That said, it's good to be aware of the risks of booking two unrelated airline carriers. I don't know if travel insurance covers this type of thing, but if it does, and you go with Option B, I'd definitely get it.

I know that some airlines ( BA etc ) do not charge baggage fees on their smaller planes if you book all the way through with them.... .for example we flew SFO to Heathrow on 747 then caught BA to Rome on a 737 with no bag fees and no collecting luggage in London.

Beware cheap flights from "Frankfurt." Some of them are indeed from the "real" Frankfurt airport, code FRA. But others are from Frankfurt Hahn, code HHN. HHN is quite far from Frankfurt (it's like saying Philadelphia's airport serves New York City), and getting from HHN to FRA takes a lot of time. So, if you're arriving at one and departing from the other on the same day, be very sure to allow enough time for this. I would only do your option B with a day of slack at each location. In other words, if I flew into Frankfurt and wanted to get on a flight to Rome on a separate ticket, I'd spend a day in Frankfurt. That way, even if my incoming flight was delayed, I would not miss my second flight. I'm quite risk-averse when it comes to flights; others would consider this an unnecessary precaution. Darren's point is also a good one. When you fly on one ticket, the baggage rules for your intra-European flight are usually the same as for your trans-Atlantic flight; i.e., much better than for an intra-European flight booked as a separate ticket, even with non-budget carriers.

Here is why in some cases online booking portals can't really help you. There are inexpensive Seattle to Rome tickets on Lufthansa (or other Star Alliance carriers) that allow you to interrupt your journey in Frankfurt. The technical term for this is simply called a "Stop in Frankfurt". You could either call Lufthansa's 800-number or a travel agent and tell them you want to fly SEA to Rome with a stop in Frankfurt on your return flight. Online you can find it out, too, but it requires reading the fine print of the air fares. If the terms and conditions of the ed fare say "stop allowed, one stop allowed, 1 stop allowed at gateway" you're fine. Other than that: Please note that Ryanair offer very cheap flights from what they call Frankfurt to Rome (vv.) but their Frankfurt airport is a two hours bus ride from Frankfurt and their Rome airport is only accessible by (pricey) taxi.