For a more accurate PC you need more information like a log-in picture / offences / quests.
If it has no quests done and simply has a firecape at 11 cb I don't think it will be worth an extreme amount, probably around 30-40M. If it has done quests though the price can get up a lot.
If you can list the quests it has done it would be nice
i doubt you will have much luck selling an account thats been reset/rolled back honestly.. especially if you "have no clue" as to why. I mean those things do not just happen out of nowhere. An account that has a tendency to be rolled back/reset is worthless imo.. you stand much to high a risk to lose any work put into it and or cash due to roll back. never the less gl selling it.
it was rolled back for trading large sums of money. Jagex don't roll back for this anymore.
It's been level 11 with cape for almost 6 months now. So I doubt it will be rolled back again.