At that price range you are better off avoiding full suspension. The linkages, rear suspension shock and frame assembly all add cost. The only way to provide a full suspension bike at that price point is to sacrifice the specifications of the components & materials that comprise the bike. These specifications make a big difference. Additionally, the linkage bearings will not be serviceable on a low cost bike, so when they wear out the bike is done.
Stick to a hard tail, the money saved in the complexity/components of rear suspension is applied to better wheels, tires, drivetrain and front shock. Also the hard tail will be more durable than the lower priced full suspension bike.