Finally, I got a ticket for Celine Dion's concert.
The price was lower than the TicketMaster's, and the only problem I've encountered was that I had to take a long walk from my hotel, New York-New York, to the box office at the Caesars Palace hotel, while the outside temperature was over 39 degrees Celsius.

It worthed the sweat. I got an excellent seat in the middle of on one of the front rows.
As the nice old lady at the box office told me: "Well, there is at least one advantage of going to the concert alone..."