Cheap tickets from Europe

I need advice on getting cheap tickets to fly out of Paris, Zurich, or Madrid to Santo Domingo between the end of August and mid September. I do not usually travel from Europe and do not know what is reasonable or not. If the fare is right, a 90-day open ticket is what I?m looking for but if not, what can you suggest? Your advice or suggetion will be appreciated!

You may want to try those links <A HREF="http://www.degriftour.fr">http://www.degriftour.fr</A> or <A HREF="http://www.tiss.com">http://www.tiss.com</A>
degritour offers left over seats to the DR from Basel/Mulhouse
TISS has a much broader selection fares are far more expensive though
good luck

pascal, thanks for the tip.