The reasonably priced regalia kit contains:
• One mad cap
• One arriviste's vest
(These items can also be obtained by playing the game.
They can be obtained in both DRAGON QUEST I and II.
DRAGON QUEST I: Open the chest inside the inn in Tantegel.
DRAGON QUEST II: Open the chest inside the inn in Midenhall.)

More details on the official game page of Reasonably Priced Regalia Kit ...