Ensure the account comes with "Registered Email" access or is "Unregistered" (rare for high-levels) to ensure you have full control. What to Look For To get the most bang for your buck without getting burned:
Pures (1 Def) or Zerks (45 Def) are often cheaper than mains because they have fewer total levels, but they allow you to jump straight into PvP or specific PvM content. buy osrs account cheap
Set up a (the new gold standard for security). Ensure the account comes with "Registered Email" access