Is it obligatory for a person of means to perform Hajj if they can afford the cost through private companies, even if the amount is high compared to state-subsidized Hajj? And would they be sinful if they did not perform Hajj and then died? And does the increase in cost and hardship lead to a greater reward?

If the cost of Hajj exceeds the usual amount (the customary price), then Hajj is not obligatory, and one is not considered capable in that instance. This is the view of Imam Al-Nawawi and Ibn Qudamah.

However, Maliki jurists hold that if a person is able to bear the cost that exceeds the customary fare, then Hajj becomes obligatory for them.

If Allah has expanded a servant's wealth, then their going for Hajj is more meritorious, and the hardship and increased cost will lead to greater reward.