I wonder whether or not there is a monetary difference between dieing as a sitting Senator and passing as a former Senator. Perhaps the type of funeral is different. IMO, either would play into the greed and vanity of both Kennedy and McCain and explain their actions.
I don’t think it’s a money issue, but vanity more than anything. I’m hoping he doesn’t end up lying in state in the Capitol (Senator and former POW - Mitch/Ryan would have to make the offer, I think). McCain won’t be buried at Arlington (his father & grandfather are there), but at the U.S. Naval Academy Cemetery in Maryland.
Ted Kennedy (died a Senator) went to the John F. Kennedy Presidential Library and Museum in Boston, where he laid in repose before going to Arlington for burial (near his brother JFK).