Ive started out with lower end Areas ethos quad and now i want to venture into the bigger little more advanced quad. Ive done some research and narrowed my choices to the following:

all are the rtf versions(my budget max is @$500-$600)
-DJI Phantom DC40(i like the includ camera)
-Blade 350qx
-Walkera 350

any advice? Right now im leaning towards the DJI.

also where is the best place online to buy these quads? Ive raced rc cars and always purchased from A-Main as they also have the quads but didnt know if theres another store that maybe specializes in these.

thanks