--snip--
It looks like the site is encrypted by "Let's Encrypt" a free SSL authority, basically you can get a free cert but it has limits (I think the limit is 3 months then it has to be renewed).
What it looks like they didn't do, is set up the auto redirect to force ssl
I wouldn't trust the site but it looks like they tried partially.
AFAIK, using wordpress or the backend of it allows free cert security. I don't know why they didn't do that or they don't really know how to. PS. I'm not web dev expert, just saw a tutorial of it that I can barely remember.
The majority will be in favor of chipmixer and everyone who used it will say good review because you can even pay what you want with it. I personally, used it and I can say that even a beginner will manage to use it.