HDB Flat

A couple of us (NP colleagues) met up with a mutual friend for lunch yesterday. She told us that she applied for a HDB flat two years ago. At that time, they (her husband and she) decided not to over-stretched themselves, so they opted for a 4-room flat.
The queue for the 4-room flat was very long and she was not successful whiles her friend who opted for a 5-room flat got his choice. The demand for bigger flat was much softer then.
She has been trying ever since and finally got her flat recently. The only problem is the price of her 4-room flat has risen so much that the price that she is paying now would have gotten her a 5-room flat two years ago. Incidentally, the increase was $100k. She is sulking now, but I told her two years from now, she would look back and say, “What a steal!”
Having said that, I now wonder what would happen by the time my children need their flats. Would they be priced out of their reach? Am I going to be stuck with them in my HDB flat?