Needless expansion.
Don't take me wrong, Livin' Large offers exactly what The Sims offers, only slightly more so, and given the outstanding qualities of the original, the expansion can't exactly disappoint. However, it doesn't offer anything important on its own to warrant its purchase. The only case when getting Livin' Large makes sense is when it is bundled in one of the game's package deals like The Sims: Complete Collection.
Bottom line: unless your life consists of nothing else than eating, sleeping and playing The Sims, or you are buying The Sims bundle, save the money for something else.