at my point of view, out of original pirce, 居屋 vs 私人樓 have many different, such as:
1. the management fee 居屋 is less than 私人樓
2. the facilities of 居屋 are less than 私人樓
since 居屋 has discount when you buy it, monthly 供樓錢理倫上會少過私人樓 (要視視乎樓價)
I bought 居屋 since I consider the usage rate of facilities is low for me (I'm a working woman) and how much $$ I can afford including 供樓, management fee....