The Hajj is a five-day religious pilgrimage going to the Mecca and the different sites in Saudi Arabia that are also considered to be holy. It should be known that this pilgrimage is not being done for Mohammed but actually for Ibrahim, which translates to Abraham. People can participate in it many times if they can.
It would depend on their physical health and how willing they are to make the sacrifice. It should be remembered that aside from the pilgrimage, there are still so many things that people have to think about such as the pieces of clothing that they will wear, their accommodations while they are there, and so much more.