As Pokémon Go spreads, so do the opportunities for buying and selling experienced gamers’ higher-level accounts. Buyer and seller should beware, however. According to the Wall Street Journal, although selling accounts may not be illegal, they could violate terms of service by both established marketplaces such as eBay and game developers themselves. Furthermore, the profits of such transactions are subject to income tax (according to the tax code, all income is taxable unless a specific exception exists). For more details, see the following full article:

http://www.wsj.com/articles/pokemon-go-players-cash-in-1468772215