Edward and Sophie have been able to rent out the old stables as office space which brought in enough to cover their rent to the Crown Estate (though the office / old stable space as on the market for rental not that long ago)OK for the house size, I don't know if I should say as maybe private or a securiry thing but Edward and Sophie apparently live or lived in 1/3 or 1/4 or their place and rest was sectioned off into self contained large flats and rented out to people who where security vetted. This may be what happens at a large part of KP in the future.
Andrew had a large house bought by the late Queen and she also bought Sarah at least one. All sold for cash then they wanted another house from the Crown estate. Although divorced Sarah apparently pushed (and insisted in living with Andrew - people think he wasn't able to move on to a sensible 2nd as she never really left) to be able to live on Royal Windsor land as she knew the value.
She has a number of other houses shared with Andrew, Portugal, Spain, New York and fornerly Switzerland and 1 or 2 homes in London. Edward and Sophie, for all anyone knows just have Bagshot they earn rental on and get to stay over at Balmoral, Sandringham. Edward and Sophie look to be small spenders by comparison who have the odd skiing holiday.
I've never heard of them renting out space in the main house, though as I understand it part of it is used as their main office space for their office / staff.
Sarah was brought a house out of the money in her divorce - £500,000 was set aside for a house for Sarah. She went through a number of houses quite quickly - I think she rented or leased a lot of them.
As I see the late Queen provided all of her three youngest children with the same - a country residence and as Monarch allowed them a place to stay in one of the official royal palaces in London. The difference is the way they were purchased or funded:
Anne - Gatcombe brought by the Queen for Anne upon her marriage and extended later by the purchase of Aston Park
Andrew - firstly, Sunninghill built on land purchased by the Queen from the Crown Estate. This was sold and Andrew moved into Royal Lodge after the Queen Mother's death.
Edward - moved into Bagshot Park, leased from the Crown Estate, after his marriage to Sophie.
I suspect part of the reason for the use of Crown Estate properties, bar the fact they are suitable properties close to Windsor and the fact that divorce wise Crown Estate leasing is better as its not counted as Edward or Andrew's property, is that although mega rich paying out tens of millions of pounds for a large country estate for Andrew and Edward as she did for Anne would eventually have diminished the Queen's capital. Income was never going to be a problem while she had the Duchy of Lancaster income so why not help her boys out by meeting the lease payments (or using Trust Funds to meet them) instead.
So I think they were treated the same by the Queen. Sophie and Ed's house is very large and a lot of comment was made about that when they moved in and even after ( which is why I think it would be much more public knowledge if they were only living in part of the house and renting out other parts of it beyond the already reported stable block). Anne's house is also big, though not as large as Gatcombe, but it has hundreds of acres of land so in that way is bigger.
That said, Andrew's personal spending is clearly much much more than the Edinburghs and Anne's. Anne is IMO old school rich - cash poor, asset rich and while happy to use private jets for official work is also happy to use the sleep train to Scotland and prefers a two person sailing yacht over a billionaires luxury yacht. Andrew is more "nouveau riche" in that he is ostentatious about wealth in a way his siblings aren't.