Once you hit level 25 on all of the main construction items including prison, alter, and battle hall. I think that there should be an area that we could either sell them off for rss or gems depending on how many we have. I have used all the bookmark and expansion scrolls for my player. There from what i have seen is no way to get rid of these items. It would be nice to have the ability to either trade/ sell them off for speed ups, gems, or some type of rss which could be used to benefit the player. It would be like the cargo ship but only become unlocked when you reach lvl 25 castle.