Is it better to perform Hajj once or repeatedly?

Hajj is obligatory once in a lifetime, based on the Prophet's (peace be upon him) saying: "O people, Allah has prescribed Hajj for you, so perform Hajj." And his silence when asked, "Is it every year, O Messenger of Allah?" then his saying: "Had I said yes, it would have become obligatory and you would not have been able to bear it." And his saying to Al-Aqra' ibn Habis: "Rather, it is once, and whoever does more, it is a voluntary act." It is preferable for a Muslim to perform Hajj frequently, due to the encouragement mentioned in this regard, for an accepted Hajj is among the best deeds, and it negates sins and poverty.