I'm not going to discuss the four way war (4e-vs-3e-vs-2e-vs-1e) that has the D&D world so often divided. Nor will I get into the merits of those systems - They're all superbly fun games. I'm just going to review this particular set of books for a really fun game.
Now, I don't own this gift set (yet), but I do own both these books (I bought the first [PH1] in the original 3 "Core" book Gift set, and the PH2 when it came out in early 2009.) For the players in your group that don't have books, or if you're thinking of introducing someone new to D&D, this is a superb deal to get people playing. (Although, they may need some Dice...) Or if you're a DM like me, you might consider getting this set for yourself just to have extra copies at the game table.
PH1 gives the player all the basic rules of character creation, Race and Class Selection, Skills & Feats, Equipment, and Combat Rules. PH2 introduces several "new" races and classes, as well as more options, including Backgrounds and new Skills/Feats/Equipment.
As for the discount on Wizard's "D&D Insider"... Well I don't use it because many of the D&D Tools aren't Mac OS compatible (DARN YOU WOTC!), but $12 is a great savings for that service (which includes Character and Monster generators, subscriptions to DRAGON and DUNGEON magazine, and a host of tools they're still working on). Personally, though, I think a set of Polyhedral Dice would have been more appropriate.
As a whole, this set is a great, solid set of books that has everything Players will need (Except Dice) to get going at the game table. That they've been offered together for the price of one is phenominal. That Amazon has further discounted that price is amazing as well, and I am strongly considering getting it just to have extra copies of them at the table.