Which is better when performing Hajj on behalf of another: choosing the least expensive option, even if it involves hardship, or the more expensive option, which offers comfort?

You have the choice to select the Hajj that enables you to perform the rituals most perfectly. If both types of Hajj are equal, then it is better to choose the one with greater expense, not greater hardship. Hardship is not sought for its own sake, but a person is rewarded according to the difficulty they endure in worship, as stated in the Hadith: "Indeed, your reward is according to your toil." It is obligatory to enter into the state of ihram for Hajj from the designated Miqat, which for the people of Egypt is Al-Juhfah, or Rabigh after the ruin of Al-Juhfah.