trying to find a ticket

Who knew that buying a plane ticket would be such a complicated process? There are many hoops that we're trying to jump through.
We can't buy a round-trip ticket because our return date is more than 365 days away. We're hesistant to get a one-way ticket because we have heard that you can have problems with customs officials if you show up without a return flight. Also, one-way tickets are very expensive. So, we're trying to buy a round-trip ticket that we can change our return flight. This is, however, easier said than done.
The other fun twist is that we probably will not be flying directly into Prague. We are trying to find the cheapest way possible to get to Europe and then we'll figure out how to get from that location to Prague. It seems that London and a couple German cities (Munich or Berlin) are going to be our best bets.
Let the adventure begin.