I think this is a nice price for all of those with SAS3 JBOD setups. Next best price I saw on ebay was for $40 without the 8643 cables. It appears the parts are modular you can get two of these and transfer the parts to one to make 16I16E. Just need the correct bracket or a dremmel
Supermicro AOM-SAS3-8I8E Mini SAS HD Int-to-Ext cable adapter with cables | eBay
Supermicro AOM-SAS3-8I8E Mini SAS HD Int-to-Ext cable adapter with cables | eBay