My oldest set of taps and dies are Japanese made BA; not good even when brand-new circa 1968. I should throw them away.
Recent purchases of inexpensive taps and dies have been much more successful. I've had good use out of them and don't expect them to last forever.
However, my most recent purchase – £4.99 from Aldi – did have faults. The 4mm tap snapped like a carrot and the 10mm die was blunt. Strangely the rest of the set is fine.
One reason for buying quality tools is that they are more consistent. This is a valuable feature when time is money, probably less so for a hobbyist. My risky £4.99 set wouldn't be acceptable in professional hands. As it is, I spent £4.99, found two duds, and the rest are good. In my amateur hands the set is a bargain.
Andy mentioned that 'price is no guarantee of quality'. Very true. Buying too expensive is every bit as bad as buying too cheap. Really we should all be after 'value for money'. That means having some notion of what you mean by 'fit for purpose' and how long you expect the item last. If value for money turns out to be Asian, that's fine. If it turns out to be a new Myford Connoisseur, that's fine too. What's not fine is buying stuff just because it's reassuringly expensive.
Dave