The Beatles Mono Box Set or The Beatles Stereo???

Both The Beatles Mono Box Set and The Beatles Stereo Box Set is on sale right now for $129. Just have no clue which one to get. I know one is mono and the other is stereo, other than that, can somebody explain to me the difference between the two and why should I pick one over the other?
I guess they used the term "limited edition" rather loosely in describing the mono box set.
The mono box set is on sale at Barnes & Noble for $120 for today only. Sale ends at midnight, Monday December 6th:
Mono Box set at Barnes and Noble
Jebe1, thanks for making me spend $120 when all I wanted to do was read some comments.