#! perl -slw
use strict;
use Data::Dump qw[ pp ];
use Algorithm::Combinatorics qw[ variations variations_with_repetition ];
use List::Util qw[ sum ];

my %objects = map{ shift @$_ => $_ } map[ split ], <DATA>;

pp \%objects;

my $iter = variations( [ keys %objects ], 3 );

my( $bestValue, @bestSet ) = 0;

while( my $set = $iter->next ) {
    my $cost = sum( map{ $objects{ $_ }[0] } @$set );
    if( $cost <= 25 ) {
        my $value = sum( map{ $objects{ $_ }[ 1 ] } @$set );
        if( $value >= $bestValue ) {
            $bestValue = $value;
            @bestSet = @$set;
            print "[@$set] => cost:$cost value:$value";
        }
    }
}

print "Best: @bestSet => $bestValue";

#object  cost($)  value
__DATA__
A       6        16
B       7        14
C       8        19
D       8        17
E       10       20