How to purchase data for a friend?

Excuse me, could you elaborate on the process of purchasing data for a friend? Are there specific steps I should follow? What kind of data is available for purchase, and how do I ensure that it's legal and ethical to do so? Additionally, is there a recommended platform or vendor that I should use for this purpose? Also, how do I protect my friend's privacy when purchasing and sharing this data with them? Thank you for your assistance.