What are they going for real life money?
You can use these threads to check for rare prices:
http://services.runescape.com/m=forum/g=runescape/sl=0/forums.ws?17,18,755,63464817
http://services.runescape.com/m=forum/g=runescape/sl=0/forums.ws?17,18,389,63461591
http://services.runescape.com/m=forum/g=runescape/sl=0/forums.ws?17,18,547,63272425
The FC Rare Quark is also pretty good for asking prices.
Based on what you find there, just convert to GP costs.
Thx got it starred. How do we know there's no manipulation on this thread?

