Where can you buy safe fast and cheap Runescape 07 accounts

Unfortunately, this is never safe. It is against Runescape's terms of use:

"Each account should only be used by one person. Never share your account with anyone else, doing so will likely get the account banned. Players may not sell, share, transfer or lend their account to anyone else. Players should not accept an account that anybody else offers, as they may be stolen, and this could lead to your own account being disabled!"

Many accounts that go up for sale are stolen, and you will never get a refund if it turns out you can't use it. Do yourself a favor, and don't make the mistake of buying an account and risking the consequences.