What kind of wealth we should seek, Preyas or Shreyas. Preyas is the search for material wealth, and Shreyas is the search for spiritual wealth.

There are two kinds of wealth – Preyas and Shreyas. Preyas is the search for material wealth, and Shreyas is the search for spiritual wealth. 

In Katha Upanishad Section 2, Yama explains the difference between Preyas and Shreyas.

Anyac chreyo anyad utaiva preyaste ubhe nanarthe puruṣam sinitaḥ

tayoḥ Shreya adadanasya sadhu bhavati, hiyate’rthad ya u preyo vṛṇite. (1)

Meaning: There are two things in this world, and people pursue either this or that. These two may be regarded as the path of the pleasant, and the path of the good. Most people choose the former, and not the good. The pleasant is pleasing, but transient and ends in pain. It is different from the good. But while the good need not be pleasant, the pleasant is not necessarily good