I'm trying to make an https version of a shopping cart website that sells bicycle gear. Before, I hosted my website on a shared hosting provider and all I did was contact tech support to enable https. I remember it only cost me about 50$/year.
Now I'm migrating the site over to a VPS and trying to set up https myself. I generated a private key and a CSR. When I went to a site like verisign, there are different types of "signing" each over 400$/year. So my questions are:
1) why is there this price difference?
2) am I allowed to re-use this certificate for more than one domain name?
3) am I supposed to buy a commercial ssl for my site in the first place? (I heard there are other free options for https websites, are they applicable to my bicycle shop website?)
EDIT
to clarify on item 3, I read about three types of ssl on linode.com library:
a) self-signed ssl b) ssl using subjectaltname c) commercial ssl
Should my bicycle shop use a, b or c? Also, My bicycle shop currently uses the magento e-commerce web application.