JOEL - The Church doesn't release any details about what General Authorities get, so any amounts of money you read about is pure speculation. I have heard other people say that no one could get rich off the living allowances they get; that what they get is sufficient for the kind of work they have to do. They receive living allowances based on their need. Some are well off enough from their own past professions that they don't need any extra money from the Church.
President Hinckley lives in a condominium in a building near Temple Square. The rest of the General Authorities live in their own houses that they purchased with their own money before they were full-time with the Church.
Consider the fact that the Prophet is about 95 years old. Most men his age would have retired over 30 years ago and spend their time taking vacations and playing golf. President Hinckley has dedicated his entire life in service to the church, and will continue to do so until the day he dies. Whatever amount he gets as a living allowance is not spent on anything extravagant; he doesn't have time to spend it on anything other than what he needs to do the work and he certainly doesn't give any of it to his kids or grandkids. He has no desire or reason to accumulate any great amounts of money. What's he going to do with it; save it for retirement? :-)
He does not own his own private jet; a member of the Church, Jon Huntsman Sr., lets him use a Huntsman corporate jet for traveling. All the money used for living allowances does not come from member's donations; it comes from investments that the Church has made over the past 170 years. Except for the tireless work he does I am sure he is well taken care of and is made comfortable. I think he deserves whatever is done for him. With how well President Hinckley does at his age, a few scriptures come to mind:

"For thou shalt devote all thy service in Zion; and in this thou shalt have strength.
And at all times, and in all places, he shall open his mouth and declare my gospel as with the voice of a trump, both day and night. And I will give unto him strength such as is not known among men." (D&C 24: 7, 12)

He is a testimony to the fact that God will strengthen those who serve Him faithfully.