These are deals from Korean online stores, so most ship only within Korea (deals marked 🌏 Usable abroad are the exception).
Plan Partners
Budget Plan 100GB+5Mbps (Millie's Library) (4 months ₩550/free)
₩550
Ppomppu · Digital
Always check the price, options and stock in the original post. Hot deals end quickly.
Product names are machine-translated from Korean. Original: 알뜰요금제100GB+5Mbps(밀리의서재)(4개월 550원/무료)