<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Do you think it's worth it to save $27 to forego the extra 1000 miles I'd get by purchasing the ticket on AA.com?</font>
$27.00/ 1000 miles = 2.7¢ per mile
The general consensus on these boards seems to be that one should acquire miles for less than that, but ultimately -- as previously posted -- the decision will depend on your needs.