Funnily enough that is against the Instagram ToS (https://help.instagram.com/termsofuse):

> 4.2 How You Can't Use Instagram. [...]

> You can’t sell, license, or purchase any account or data obtained from us or our Service, regardless of whether such data was obtained while logged-in to an Instagram account.

> This includes attempts to buy, sell, or transfer any aspect of your account (including your username); solicit, collect, or use login credentials or badges of other users; or request or collect Instagram usernames, passwords, or misappropriate access tokens.