United and Delta have round-trip flights from Houston (IAH) to Berlin (BER) for $618-$631 with a connection. Flights March, April, October, November, and December. Departures on Monday, Tuesday, Wednesday, and Sunday. 7-day minimum stay required. Holiday blackouts.
A Carry-on bag and also a personal item is allowed for free on Delta. You can avoid paying for seat selection by accepting the randomly assigned seat at the gate.