Asking this because my nephews birthday is in July and he loves Pokémon, so setting up a cool binder for him and trying to get a diverse range of cool arts (His favorite Pokémon are: Pikachu, Charizard, Lugia, Walking Wake, Zeraora, and Mew).
I have a $100 budget and trying to make the most of it by mapping out what to buy 
imo with a 100$ I think modern is the obvious choice. If it was me I would focus on the AR and the CHR from the last couple sets as the art is beautiful and is cheap so a lot of variety. The last time I checked ARs are a few bucks each. Obviously a binder is also needed.
https://www.elitefourum.com/t/jp-special-art-pokemon-card-gallery-sv/40918
This thread was very helpful for me making a binder of ARs.
You can also throw in a couple boosters for that opening fun.
$25 hit card
$25 in $5 hit cards
$25 in $1 CHR and AR
$25 in commons with cool art, reverses, bulk V/EX of popular Pokémon
Teach him there is way more to collecting than just the big hits. The $25 hit is to have one in his binder that is the best of the bunch
Definitely chuck these two in if Japanese is on the radar (maybe not this exact Ebay listing—this just happened to have both cards). These were printed so massively that they ended up being really cheap. And like others have said, ARs /CHRs are huge bang for your buck for cool-but-cheap cards.
I think it depends on how old your nephew is and how much they know about TCG collecting.
I remember the best part of being a kid was pulling hits myself and organizing my collection.
I’d try to replicate that with:
Open some packs, place a hit in them and reseal. I guess it depends on how much your nephew knows about the TCG, but if they’re just getting started, it might be a nice way to guarantee they have a nice pull experience.
A lot of the other ideas posted above are fire, like you could pre-make a black and gold art UR binder for $100 too and as a collector that is a pretty good way to stretch your budget, but as a casual child collector the best part was opening packs because it feels like you “earned” your collection.
I would definitely set him up with a nice cloth binder, small pack of penny sleeves, a couple of his favorite Pokémon’s cards (nicer ones preferable) and then spend the rest on packs for him to rip. I guess just what Banks said haha
buy things using the e4 ebay affiliate links #notsponsored
Agree with this. I’ve been selling and giving piles of bulk for parents who have given them as gifts for their kids and the sheer amount of cards is often overwhelming to them, so even though some kid scale big hits and sparkles are probably what catches their eye i too root for getting some amount of nice bulk cards. Some artists like Shinji Kanda perhaps would be exiting since that unique art for kids can feel very special compared to stock art. But i also agree that throwing in few packs doesn’t hurt since kids usually do love that.
Ancient mew then a few SWSH trainer galleries or SV IRs.
Definitely get some crown zenith packs!! Those are loaded with beautiful cards
+1, IMO this is the perfect answer. Collecting is a journey and involves discovery. Thinking back to my own childhood, the cards and Pokemon I feel the strongest connection to are ones I pulled myself, or, to a lesser extent, acquired for myself through trades / purchased from my LGS. At the same time, any single cards you give him will have an instant sentimental attachment for him which has value beyond money. Practically speaking, he’ll of course need sleeves and a binder. Banks’ suggestion combines all the above - the discovery (packs), the acquisition of nice cards to buffer the collection, the sentimentality, and the practical needs met.
Edit: Tyranids brings up a good thought - Ancient Mew or another iconic vintage card would be a great addition, you can tell him the story behind it and introduce him to the boomer side of collecting.
+1 for bulk and packs. 1,000 bulk cards for $30 might be a great starting point. I bought some bulk myself when I was building out some artist collections.
Thank you everyone for the input. I ended up deciding on getting him a lot of vstar universe stuff, some ARs from SV, and a Van Gogh Pikachu.
C:
My generally rule for ‘cool’ considerations is, if I think it is cool looking the nephew is going to think it is awesome looking.
