Automatically redirect from www to non-www url on Wordpress site

I am going to buy a SSL certificate. My webhost say it do not matter if I buy a www or non-www certificate. My site is a and not a website. My webhost say that if I buy a certificate with www, the ssl will work on both www and non-www on my site. If I buy a certificate without www the ssl will only work on my domain without the www in front. If a user typess www first, then my ssl wont work on it. So do you think I should buy a certificate for even that I have a domain without www. My domain is By the way, when I did install Wordpress I pick the option with an url without www.