You might want to utilize RSorder in order to market your Runescape accounts and gold. If you are interested in RSorder you can contact them via live chat service and make an "sale gold" request. When they receive your request for sales they will reach out to you via message or Skype message and give you an affordable price. Once they have confirmed the sale by contacting you directly, you are able to opt to receive immediate cash payment via PayPal, G2A, Skrill or Bitcoin.
I've used this site numerous times and found it to be highly secure and reliable! They're extremely professional and their service is excellent. Visit RSorder to test it. I hope you get a good price!