SSL certificates. Help find the path in the dense forest

Hey.
Faced the problem of choosing an SSL certificate for your project. The topic turned out to be extensive for me so much that I just don’t know which side to approach its solution and therefore I would like to ask knowledgeable habrapractors to chew me and colleagues in the habra-shop (with similar interest) about all the intricacies of SSL certificates.

“What really is the matter with them?”
“Why is the difference in cost so great? What does it depend on? ”
“ Is it worth it to rely solely on the price, or are there serious technical aspects? ”
“ If I switch from one host to another, will the certificate lose its strength? ”

For example, my host offers several options (price for a year) :

GeoTrust QuickSSL Premium Certificate - 5000 rubles
RapidSSL Certificate - 800 rubles
RapidSSL Wildcard Certificate - 8,000 rubles
Thawte SSL123 Certificate - 3,000 rubles,

which for example, and why?

Thank you in advance for your understanding and assistance.