Fair question:

But keep in mind, they didn't list 'Legacy' as part of the billing plan because it's not obtainable anymore. So rather than field 4,000 'how do I get the Legacy rate?' questions, they just didn't list it.

I'm going to assume, that Legacy player can also pay in 1,3,6 month increments, but we just don't get an additional savings. So regardless of how many months we pay for up front, each month costs 9.99

(would be nice to get clarification of course)