Short verdict
Buy in Korea. Best purchased during a Korea trip, usually because of local access, price, testing, or limited bundles.
Stationery is one of the easiest Daiso categories to justify because it is small and Korea-specific designs can be hard to replace.
What to know
Buy stickers, memo pads, simple pens, cable labels, and compact notebooks if the design is the reason you want them.
What to avoid
Skip heavy notebooks, generic office supplies, and anything that bends easily in luggage.
Final verdict: buy flat, light, Korea-specific designs.