The budget travel in Japan vs budget travel in South Korea comparison comes up constantly and the answer is that they're different experiences at similar (but not identical) price points.

Japan budget summary:

• Accommodation: capsule hotels ¥3,000-5,000/night, guesthouses ¥4,000-7,000, hostels ¥2,500-4,500 dorm
• Food: cheap if you use convenience stores and standing restaurants ($8-15/day)
• Transport: expensive unless you have a rail pass; budget $15-25/day for city and regional transport
• Activities: temples and shrines often free, major museums ¥500-1,500
• Daily total: $60-80 realistically, $50 aggressively

South Korea budget summary:

• Accommodation: motels (jjimjilbang as overnight alternative) ₩25,000-50,000/night ($18-38)
• Food: cheaper than Japan, street food excellent, Korean BBQ lunch sets affordable
• Transport: Seoul metro ₩1,400/ride ($1), excellent coverage
• Activities: palaces and national museums very cheap or free
• Daily total: $40-60 realistically

For pure budget, South Korea is meaningfully cheaper than Japan. For overall experience per dollar, both are exceptional. My recommendation: do South Korea first if budget is the primary concern, Japan if the cultural experience is more important than the budget. Both are worth doing if you can manage either.