So there are indications that pretty soon all the popular kids will be wearing SSL certificates. Google is issuing some indications that it will smile on sites with ssl certs (ie, it is now a ranking signal), so getting one for your site is not a bad idea.
You can pay GoDaddy approx $65 for one, or you can get one for free from the kind folks at LetsEncrypt.com. They also have a handy list of web hosts that will work with them. Unfortunately, GoDaddy is selling SSL certs so you are out of luck to do that one for free with them; however, I did find a 25% coupon with about a second of searching, so at least you shouldn’t have to pay full price.
An SSL only used to be important if you accepted credit card payments on your site, but now Google is pushing them to make the web more secure in general. You can get by still for a while without one, but not having one will eventually affect your SERP negatively – so get on board!