Mike, while I am FAR FAR from being one of the worlds most experienced traveller's.... I could recommend this, First of all, right now, if you are tyring to book your flights for the next month or two... air fares are NASTY! Period. Even discounted routes are up a couple of hundred dollars round trip. I know it may be kind of difficult if you are like me and you like to get those plane tickets in your hot little hands, but try to wait until September to book, the flights should go down considerably. Then try fly out or back in the middle of the week... Since Friday Sat, Sunday travel is more expensive...if you have any flexability that is. Try to go through a consolidator and hit up a few travel agents just to see if they come up with a better fare, again, do this in September.
Now about open jaws.. Usually it is a bit more expensive to fly into a place and out of someplace else, but get some different price quotes, then see what it would be if you booked say RT tickets from SF to London and add on a connecting flight from Rome to London, we did this once and ended up saving about $150.00 per ticket by NOT having an open jaw, but rather adding on a cheapy-connecting flight. Really it all depends but you need to shop around, good luck!

Mike, sorry if I was a little unclear... If you are trying to book your flights NOW or anytime during the peak season, even if you are travelling in October, you will pay more then if you wait to book until September. Example, we are planning a March trip to London, if I search for fares now, I end up getting $800-$1100... per ticket.. when traditionally March fares are around $300-$600.00 so I am better off waiting until closer to the departure date, October is the same deal, though not quite as inexpensive as March, you will get better prices if you wait (hope that made more sense, it's early here).

Try http://www.affordablepoland.com (not just for Poland air travel) - - click on "airline tickets".

Best wishes,

Rex