Bureaucracy and ECP will make lot of money in the procurement of EVMs. 300 billion mein to achhi khaasi corruption ki ja sakti hai. 10% of 300 Billion is 30 Billion.
One time cost and they can be used again and again. The only question will be the design. It shouldn't be something where they have to completely change the device in future due to a glitch or some new requirement.