Two blocks or unlimited + block?

I almost exclusively get current/new releases. My usage is ~60 GB per month. I currently have a 6TB block and was going to use Black Friday to pick up an unlimited... BUT, I was wondering if for my (seemingly low?) use case, would it be better (i.e., more economical) to get a second block on a different backbone instead? Since 6TB at that usage is several years' worth?