1. Go to the Phoenix Cave with Locke in one of your parties. Steal from the Apuila (A bird creature) and you will get an Economizer. Try several times because sometimes you'll just get Fenix Downs.

2. Go to the forest east of Gau's father's house. Sometimes a Brachiosaur appears. Fight it (VERY HARD) and sometimes it drops an Economizer.

3. Go to the Coliseum and bet a Gem Box. If you win the battle you'll receive an Economizer.

Cursed shield is from an old man in Narsh after you get the Falcon Airship. Equip the shield, and win 255 battles with it. That will break the curse...and thus, you will now have the Paladin Shield.