As a long-time MTG player who has recently picked up the Pokemon TCG, hopefully I can be a bit helpful in terms of product equivalencies. The products listed at the bottom, which don't really have an MTG analog, might be best suited for what you're trying to pick up.

• The Elite Trainer Box is the Pokémon equivalent of a Fat Pack in Magic (the MTG gift box is a bit different and doesn't really have a Pokémon equivalent). It comes with 8 packs vs. MTG's 9, but also includes a pack of 65 sleeves, a set of D6's with the set's logo (rather than a single spindown), and acrylic versions of the cardboard counters you get with a theme deck.
• Theme decks are just like Magic intro deck, except it does not come with two boosters. Instead, it comes with a code to play the exact deck in the online TCG, as well as an additional non-holo copy of the rare holo in front (MTG into decks only have 1 copy of the foil rare face card).
• Battle Arena decks are somewhere between a MTG Duel Deck and Clash Pack in that they come with 2 ready-to-play 60-card decks, except they come with multiple copies of the EX face cards (unlike the Duel Decks), and are not meant to be combined into a single deck later (unlike the Clash Packs). They also come with multiple copies of a variety of useful high-value (think $4-10) trainer cards, which is something that is unlikely to be found in an MTG pre-constructed product.

Pokémon also offers a variety of products that don't have an MTG equivalent, such as a bunch of packs and other tchotchkes (notepad, pencils, stickers) in a tin lunchbox, 4 packs and a promo card in a metal storage tin, blisters with between 1-3 boosters and a promotional card and coin, and boxes with multiple packs, promo cards, and either pins or small figures. One of these latter products is probably best for your purposes as they'd fall within your budget, guarantee a flashy promo even if the content of the packs is a dud, as well as provide the excitement of cracking packs. You can, as others have suggested, choose the promos that align with the gift recipient's favorite Pokémon. Keep in mind every single booster comes with a code for a randomized booster of the same set in the online TCG, so if the kids enjoy that then they'll get to open each pack twice.