-# my $custnum = $self->custnum;
-#
-# my $owed_sql = FS::cust_bill->owed_sql;
-#
-# my $sql = "
-# SELECT SUM($owed_sql) FROM cust_bill
-# WHERE custnum = $custnum
-# AND _date <= $time
-# ";
-#
-# my $sth = dbh->prepare($sql) or die dbh->errstr;
-# $sth->execute() or die $sth->errstr;
-#
-# return sprintf( '%.2f', $sth->fetchrow_arrayref->[0] );