Should I go for dedicated SSL or free shared SSL? What's the deal?

I have two questions about SSL certificates that I'm hoping you guys will share your experience and thoughts on.

Question 1:
How important is it to have your own dedicated SSL certificate vs. using the free shared SSL certificate? Have any of you guys noticed a loss in customers or orders or any negative side effects at all from using the free shared SSL certificate?

Question 2:
What are some good places to buy SSL certificates and what's a fair price? I've contacted Verisign and their prices are beyond my budget.

Thanks.

P.S. My apologies if these questions have been asked and answered before.

Private SSL will use your domain name and will not cause any warnings messages, it can be very advantageous for your online store and web presence as its issued especially for your domain name by a trusted authority.

Shared SSL is installed globally on the server and configured to be used from all users on the servers. The shared SSL certificate generated for the hostname of the server and it will cause a certificate warning message pop up on your site when it used as it's not matching the domain names.

I have two questions about SSL certificates that I'm hoping you guys will share your experience and thoughts on.