Buy and sell Reddit accounts

Yes. Reddit's User Agreement doesn't allow accounts to be sold without Reddit's approval, and Reddit can suspend an account that has changed hands. That risk is yours as the buyer: escrow protects the payment, not the account. Be wary of any listing that says Reddit has approved the transfer.

How old it is and where its karma came from. Modest karma spread over years and many subreddits looks like a real person. A pile of karma earned in a few days on meme subreddits doesn't, and gets flagged more often. Karma in the subreddits you plan to use matters most, because many of them set karma or age limits.

Ask for the username and look at the public profile before you agree anything. Post history, comment history and account age are all visible without logging in. Check they match the listing, and look for gaps or a sudden change in writing style, which can mean the account was sold before.

The email and password first, then two-factor on your own phone, then remove every connected app. Accounts used for promotion often still have a posting tool connected.

Most subreddits ban open promotion whatever the account's age, and moderators are good at spotting an account whose style suddenly changes. An old account only gets you past age and karma limits. The subreddit's own rules still apply.