While surfing the Ask Experts section, I came through this thread and found no relevant answer to your question as nobody has got proper cs and points for their answers. So, let me try to answer your question.
Firstly, I may say that some companies possess a name and fame in the market like that of Nokia, Samsung, Sony etc which effect the prices of the products as being the great producers of amazing products.
The companies like Karbonn, Micromax etc are new to this market and they first need to increase their standard to build the full trust of the customers. Also, these companies use assembled parts i.e. the internal parts are not all of the particular company rater it is brought from the other sources like China etc which comparatively lower the prices of their products in the market. Moreover, when a product is launched, it first undergoes evaluation through different authorities which review it and then give the approval to launch this product at a given rate and seeing the assembled parts or any other defects in the system of the products of these companies, they give it a lower price category.
"For quitters never win, for winners never quit"
Syed Musaddiq Andrabi