both have their pitfalls
buying an account means that it can be recalled, something that happens alot. so if you buy one, make sure it is from someone extremly reputable, and that they either are the OO of the account, or offer a money back guarantee on it
powerleving? make sure the company does it by hand and is not sub contracting the work out to the chinese who will get your account banned. alot of companies claim they only use handlevers here in the states, but for most, not all but most are not being honest in this regard
best of luck