If you find any kai seki magoroku knives in TKMaxx, they're probably a good shout.
Got one of their 4000ST nakiris for about £15-20, seems like decent steel, holds super sharp edge, packaging is written just in Japanese and suggests using a whetstone for sharpening for that authentic feel!
Are they? That’d be surprising, but not impossible. Might have a look in TK this week.