Money does drive electronic voting
I am not as cynical as some, but the adoption of electronic voting in the US was certainly driven in part by money. There was the mess in 2000 in Florida, followed by hundreds of millions of $$$ raining down from the federal government to upgrade voter systems. In 2000 electronic voting machines were a very expensive solution looking for a problem to solve, and suddenly they were affordable. Everything is "cheaper" when you are spending grant money, and electronic voting companies were like a monorail salesman in a certain Simpsons episode.
The other part that drove electronic voting was access - handicapped rights groups and immigrant rights groups joined hand-in-hand to demand the computer-based voting machines because they make access modestly better - video screens can expand text for the visually impaired, and once you have translated the ballot to another language, there is no extra printing costs to keep enough ballots on hand in each language. And it is hard for many politicians to say "no, it costs to much" to such groups.
The cost? My community spends ~$14K per optical scanner for paper ballots (one per precinct) which last 15-20 years, ~$1.5K per machine per election to program the chips, and around $2K per precinct to print ballots (plus staff, etc). We spend $50 per voting booth (heavy folding cardboard) that last 8-10 years; we have 50 booths per precinct. We also have one booth per precinct at a table with a fancy magnifying reader (~$500) to blow up the paper ballot for the visually impaired. We get initial vote counts 2-5 minutes after the polls close (excluding write-ins).
If we had computers, that is $3K-$5K per voting machine. Several $hundred per election per machine to program - less per unit than our $2K/optical scanner because of volume, but much more in total, OTOH no printing costs. The voting booths would be wood or metal due to weight, which aside from cost (not sure how much, but I'll guess ~$250/booth), means more storage space between elections and more labor costs to set up/tear down. And after 10-12 years, the machines are near their end of useful life (http://thehill.com/policy/cybersecurity/222470-states-ditch-electronic-voting-machines). Since they whole setup is so expensive, you buy as few voting machines per precinct as possible, which means longer lines than paper ballots - which can yield (somewhat ironically) less access. My state requires a minimum of one precinct per 6,000 residents, so pick a community size and you can do the math to guesstimate the cost. The bottom line is, if paying out of local taxes, very few communities would choose electronic voting over paper ballots.
And if you lose power or have other technical problems, those paper ballots can be counted by hand. With electronic voting machines you're screwed (and that has happened).