Selling big house, downsizing in Noida — confused!

Kids have moved out, socha Noida mein smaller flat le lete hain. Don't need such a big place anymore. Resale se jo paisa aayega, it'll help with retirement. I'm looking at Sunworld Arista, ready to move hai isliye. Supertech Neerajanil bhi dekha, but under construction mein darr lagta hai. Sunworld ka price is thoda zyada, but at least you know what you're getting. Honestly not sure which way to go. Which one has better resale value in the long run? Also, maintenance charges kiske kam hain? Need something manageable. Proximity to a good hospital is important too. Any opinions?