To clear up the options you have to choose from for your site, the difference between an SSL certificate and just our Secure Send service.

On top of your base monthly cost:
If you add the SSL certificate to it, add $15/mo.
You can pay the SSL certificate annually for $150 to save $30 vs. the $15/mo.
If you add the Secure Send to it, add one-time $50 setup, then $20/mo.

To decide whether you want the SSL certificate:
An SSL certificate enforces that the site content shown has not been tampered with by some criminal, that the content shown is what the site owner wanted to give to the person viewing the website. Also it ensures that any info typed in to the website is kept private and encrypted. Having an SSL certificate does not encrypt file attachments that other people upload to your site. More info on SSL certificates here https://help.dollaradaysites.net/knowledgebase.php?article=37

To decide whether you want the Secure Send: 
The Secure Send feature simply lets visitors of your website be able to securely upload files through your website to you, keeping you compliant with security and privacy standards of your industry.
There’s no software for your customer to learn, all they do is visit the page on your website.
Rather than wait on people to bring documents in-person, or send by post office/fedex/ups, documents can be sent instantly to and from you.
Files that are normally way too big for email are no problem.
Systems like dropbox and google drive only encrypt files at rest on their servers, the file doesn’t always get encrypted in transit while uploading. Our service encrypts the files while in transit AND while at rest to meet your compliance needs.
The Secure Send will have its own separately secured page on your website, so it’s not mandatory to also have the SSL certificate just to be able to run the Secure Send.