The game itself is free. You can buy and sell accounts/gold/membership here. I'd suggest you buy a runescape account along with membership, since its way easier/cheaper to buy it.
wow!they so nice u know giving it 4 free.so i buy account.like wat if i start from da begining like 0 everythin.completly start frm sctrach then coud account be free?i like earin evethin on my own.where do i buy acount?