I bought Lumia 630 dual sim for 180 US $ when it was released in the very beginning sale of the device as I wanted to use latest Lumia at that time and I couldn't afford for Lumia 930, now I can get the one brand new with even for 60-65$ , I think Nokia/Microsoft cheated us.
The build quality is nice, but the gap between screen Gorilla glass 3 and front corners of the phone is much and is an issue, the creaking of phone can be felt in some areas when pressed with medium pressure, the software buttons cannot be hidden it is also annoying, the back light bleeds in the screen corners, particularly in the uppermost part of the screen while with white background, the camera is not as good as other 5 MP cameras in other Smartphones.
The apps are not very much quality ones and many popular apps are not in par with those with other Mobile OSes and the resuming, loading screen while switching between apps is very annoying, and the Lumia 630 also hangs sometimes.
I am considering buying new phone only if the Lumia has smooth OS, all wanted qualitative apps to be found in Windows 10 store, no resuming and loading screens, hardware with no serious faults, zero gaps between screen and frames, solid build quality, nice camera with dual tone dual led flash, latest processors(except octa core processors, Snapdragon 615 and 810), Gorilla glass 4, and price around 300 US $.
And I am using Windows 10 TP on my device now, and I want some serious revolutionary change in OS and apps quality and availability (which I haven't seen much) which I hope would be seen around it's Final Release( I hope).