In my opinion, there should be no padlock, no visual indicators that a connection is secure for DV certs. The enduser doesn't have to know a website uses HTTPS. The padlock should only show up (along with the company name) when the website uses an EV certificate.
I'm also in the position of running a small online business on the side, and such a change would almost certainly require and upgrade to an EV certificate. While we have thought about it (and I have tried to find some data on changes in conversion rates possibly coming from it), I haven't quite been able to convince myself that the costs and hassle are worth it.
The process may be prohibitively expensive in some countries, or for some very small operations.
Maybe it's time to think about improvements to identity-verifying certificates. Either by improvements to the process towards automation, or maybe another certificate class relying on a reputation system for judging trustworthiness.
The security benefit is that the connection to the server is authenticated and encrypted. Nobody in between can inspect or mutate the data. This is a huge win over unauthenticated HTTP.
Have you ever heard a regular user talk about the URL bar not being green?
[1]: https://www.chromium.org/Home/chromium-security/marking-http...