May roundtrips on AA NYC-MAD are running about $558+ for M thru Th flights routed through MIA. With the tax and everything it runs about $629. I just checked a number of days and all were available.

Edited to add: You can also buy a NYC-LON ticket for $389+ and a separate LON-MAD for about $115+. It should total about $625 or so.

[This message has been edited by jerry a. laska (edited Feb 13, 2004).]