The Splatoon 3: Splatsville Shopping Bag is 800 Platinum Points for a bag clocking in at 15.35” x 15.35” x 10.62”. Here's how Nintendo describes it: "Shop 'til you splat with this roomy and reusable shopping bag inspired by the Splatoon 3 game. The full-color design around the exterior features stylish ink splats, brand logos, and more from the world of the Inklings and Octolings. Wrap your tentacles around the two colorful cloth handles for ease of carrying (or maybe even hanging the bag...on a hook?)." There is definitely no shortage of bags at My Nintendo! It's like a cottage industry over there.
The Graffiti Sticker Set is 400 Platinum points, and are 5.5" H x 12" L per sticker sheet: "Splat up your surfaces with this set of stickers inspired by the Splatoon 3 game! Featuring 49 durable die-cut stickers across three sheets, this reward can be a great way to add a fresh touch to your notebook, skateboard, helmet—or whatever else you can think of!" Stickers have been less plentiful than bags, but there's been a few offerings since My Nintendo was launched; including an original Xenoblade sticker set.
There's also a Splatoon 3 contest going on right now through October 5 at 2AM ET. You can spend up to 30 Platinum Points (10 per entry) to attempt to win the sweepstakes, which involves a prize pack of a mini locker (meant to replicate the in-game mechanic), a Switch case, a backpack, and a water bottle.