[c0ncrete]

use 5.012;
use warnings;

package NPC;

sub new {
    my ( $class, %param ) = ( shift, @_ );
    $param{_class} = 14;
    return bless \%param, $class;
}

sub GetClass {
    shift->{_class};
}

package main;

my $npc = NPC->new();

# array of playable class long names
use constant CLASS_L => qw(
  Unknown Warrior Cleric Paladin Ranger Shadowknight Druid Monk Bard Rogue
  Shaman Necromancer Wizard Magician Enchanter Beastlord Berserker
);

# hashref containing buffs offered depening on the class of the npc
my $buff = {
    Enchanter => [
        [ "Bind Affinity",      35,   10 ],
        [ "Breeze",             697,  25 ],
        [ "Clarity",            174,  50 ],
        [ "Clarity II",         1693, 200 ],
        [ "Alacrity",           170,  10 ],
        [ "Augment",            1729, 30 ],
        [ "Aanya's Quickening", 1708, 100 ],
        [ "Rune I",             481,  5 ],
    ],
    Necromancer => [ [ "Dead Men Floating", 1391, 10 ], ],
};

# this is what the client said (used to search available buffs)
my $text = "la";

# this is how we find out long name of the class the npc is
my $mclass = (CLASS_L)[ $npc->GetClass() ];

# this searches the array of available buffs and returns only those that match
foreach my $spell ( grep { ${$_}[0] =~ /$text/i } @{ $buff->{$mclass} } ) {
    my ( $spellName, $spellID, $spellCost ) = @{$spell};
    say "I can cast $spellName [$spellID] on you for $spellCost platinum.";
}

results:

I can cast Clarity [174] on you for 50 platinum.
I can cast Clarity II [1693] on you for 200 platinum.
I can cast Alacrity [170] on you for 10 platinum.