Divers den stuff is pretty much impossible to add to a group order due to the real time nature of the WYSIWYG. They would prob try to work it out- and it would be killer- but would be tricky. They also ship from two locations One out west and one in wis. The divers den stuff is in wis along with I think most of the coral. Many of the fish are on the west coast. In case of a mixed order there is a additional shipping charge I believe- although much lower than the initial rate. The items also obviously will come a diffrent times also.