Bluehost allows dedicated IP address to customers for just $2.5 monthly ($30 a year). There are several reason why you should buy a dedicated IP address:
To enable SSL on your website: SSL is Secure Socket Layer, allows you to securely transfer data between the server host and the client machine. With SSL installed on your server you can access your site securelt with https.
To run software on your website: Some software requires some ports to be opened for it to work. On shared IP address it is impossible to open specific ports but on dedicated yes.
Better ranking in search engines: Although this is a myth, it is good to have your website on different IP address. Many people have reported that dedicated IP address helps for better rankings.
You can access your website just by using the dedicated address.
To buy dedicated ip address from bluehost you need to login to your cpanel account and choose the dedicated ip tab to purchase.