How old is your laptop?
If you replace the motherboard and it is like it was before, are you still satisfied with its' performance and what it can do or were you starting to wish you had something better?
How much is a new laptop in relation to the 12,000 rupees for a new motherboard?
Is it better to spend a little more and get a new laptop with the usually 12 month manufacturer's warranty as opposed to a replacement motherboard with perhaps a lesser warranty.
The repairer should give a guarantee on their work and perhaps there may be a warranty on the motherboard.
These are the questions that you have to ask from the people you get the motherboard from and who will do the work (if they are not the same person)
If you decide to get a new laptop, you may be able to recoup some of the cost by selling the faulty laptop for parts, after all, presumably the screen still works etc.
You may have to do some research as to which is the best option for you.