Hi Russell Thak you very much for your comments and suggestions.
Russell Said
I find you have to look beyond just the item cost of the pcb. The issue of labour (especially in testing) tends to outweigh the pcb cost

By using two boards i.e. by using a single sided board for DC inputs and AC outputs I will be saving approx. 200 Rs. per unit.

In India labour is very cheap I can easily hire a worker for Assembling and testing for less than Rs. 7,000 per month. If he assembles & tests 10 boards a day than assembling & testing labour cost per board is approx 23 Rs.

Even If the assembling & testing cycle time reduces by 50% [ Worst Case ] due to inconvinience by 2 separate boards the extra cost per board will be approx 10 Rs. which is far less than savings acheived per board [ Rs 200 ] by this approach.

Thanks & Regards,
Prahlad Purohit