I am looking for the most affordable wildcard SSL certificates. Do you know where I can get them?
you can get them for free with https://letsencrypt.org/
I use cloudflare.com that provides free SSL for my static websites, and letsencrypt on my WordPress websites. Both are great free options.
There is AlphaSSL WildCard for 50ish per year. However if you can set the letsencrypt automated renewals this will be the best free option you can get. Cloudflare requires the CDN to be enabled for the free SSL to work, if that is not a problem that is the easiest.