There are 5 of us going on the Harmony sailing July 8th. I want 4 of us to be able to have wifi at the same time and 4 of us are diamond members. The current price is I buy 4 is $434. I know 4 of us will receive one free day and maybe a Diamond discount?? I can't figure out the most cost effective way for four of us to have access during sea days. Any suggestions?