I am planning to buy 3BHK flat in ATS Happy trail sector 10 Noida extension , is it a good option and what should be price of the 3BHK flat

Just 15 minutes drive from NH 24, ATS Happy Trail is located in Sector 10 Greater Noida West, 201306. From what I know this a residential project with many indoor and outdoor amenities such as indoor badminton court, table tennis room, multi purpose hall with pantry space, gym, kids play area, amphitheater, rainwater harvesting pond, party lawn, open lawn, basketball court, cricket pitch, etc. as fas as connectivity is concerned I believe it is just 20 minutes from Noida City Center and there are many facilities for commutation available. 

Besides, Noida and Greater Noida area have a lot of commotion with many commercial and residential setups. You can enjoy a day out with your friends and family to malls, cafes, restaurants and other entertainment centers which are close by.

The 3BHK flat price in Sector 10 Noida in ATS Happy Trail is Rs. 4620.93 per sq ft. 

I would say you can have a virtual or physical tour to ensure that each aspect is perfect and then invest your hard earned money.