Generally speaking, people do not contact demons without reason; after all, demons are not readily contactable. Many of the common methods for contacting demons found online are false; a genuine Demon Magic Circle is exceptionally difficult to inscribe.
The Demon Magic Circle exists precisely to allow demons from another dimension to sense this location so that their power can extend here.
Breaking through dimensions is not an easy task. Even if one knows the pattern of the Demon Magic Circle, gathering the materials and mastering the correct strokes is not simple.
Ordinary people really struggle to contact demons unless they have a unique constitution from birth.
Dio contacted a demon, which certainly was no small matter. Judging by the A4 papers Daenerys selected for his house hunting, it was clear that Daenerys's family was incredibly wealthy.
Thus, it was unlikely that Dio sought to contact demons for wealth.
