As far as $20.00 value goes:

In most games with Mounts and Cash Shops:
Mounts ~$15-25
Pets (Minions) ~$10-20
Helms ~$5
Gear Sets ~$10-20

The Barding is a set of 3 pieces, hence listing it as a gear set. So if you were to price-out each item separately you'd be spending around $40.00-70.00 for the items. Don't forget that you get these items on each and every one of the characters you create, thus if you redeem them multiple times, you save yourself even more.