If Biden was taking his time off at Camp David, I wouldn’t care as much, it’s government owned and the infrastructure to protect him is always there. But when any president goes to stay at a private residence, especially one that belongs to someone else, the costs are staggering. A lot of things that most people would never consider. The local phone company has to install dedicated cables for the private phone system that travels with the president. Every manhole and access point for those cables has to either be welded shut or guarded 24/7 while the phone system is active. The air space anywhere near the presidents vacation home has to be closed to all traffic. The Air Force has to station alert fighters at the nearest air base and if there isn’t one nearby, fly CAPs. All utility access have to be secured or guarded. All manholes on any possible route for the motorcade to the vacation house have to be welded shut and surveillance mounted on all the potential routes. As we recently saw in Utah, anyone who might be a threat to the president has to be detained or put under observation. Just a weekend visit is mind-staggeringly complex and expensive. At least if a president goes to his own property, the facilities can be reused and is a little more cost effective.