It may be that he Secret Service is not allowed to accept free accommodations. They have a budget for such things and if that money is not spent there may be issues in the future. Believe it or not, many agencies are very careful estimating costs for the upcoming fiscal years and if they end up with a surplus or deficit it causes problems (due to expiration of funds).
This story really needs more research to determine if it really is a story at all.
Because the Trumpster is not taking a paycheck like Zero did, The "Atlantic" is trying to sell the idea, that POTUS Trump is making up the difference via housing charged to Secret Service.
It's not that I don't TRUST the "Atlantic," it's that I FLAT-A$$ don't trust them, now having dealt with my trust issue's, it's time to use the fish wrapper, to wrap some fish.
PS POTUS Lied to me, said I would get tired of WINNING!
NOT!!!!!
BUT, if they were paying the full amount, it would not be a good idea for Eric Trump to lie about it.
Lies are always a deep hole to fall off into.