As you said, Celkon Campus A35K is one of the best budget smartphones in its price range.
It comes with the following features and specifications:
- Android 4.4.2 OS (Kitkat)
- 512 MB Internal Memory
- 1 GHz Processor
- 3.2 MP Rear Camera
- 3.5 Inch Display
- 3G Video Calling
Definitely, it's one of the good choices in its price range. However, if you can shell out one thousand rupees more than, you can go with Karbonn Smart A12 Star, which packs pretty good features than Celkon Campus A35K at a price of Rs. 4099 only. Nonetheless, it's you who has to decide. Hunt on Google to get yet a clear idea on this.