There's not a ton of other reasons to seek out this product, so Steam Siege is a great example of a set you'd be better off buying singles from, rather than shelling out the money for the sealed product
good on Rusty (as always) to make that clear, even at his expense
However, this move can bypass the first-turn restriction on playing energy, making it a potential first-turn play
As you pointed out, the difference between Pokmon EX and Pokmon GX is that the former ones are always Basic whereas the latter ones are always the stage they are supposed to be [1] (except for Tag Team GX cards which are also always Basic)
Number 35: Ravenous Tarantula and Number 84: Pain Gainer have very similar designs and the same stats, but differ in their effects and being one rank apart (35 being Rank 10 and 84 being Rank 11)
Like many other tabletop games, its extremely easy to learn but can take much longer to fully master