If by "basic set" you mean something like this here, 500 dollars is not really crazy expensive but just a fraction of what the Axminster originals cost. Although the small spigot jaws seem much shorter.

The bigger issue I have, just from the Amazon offerings, that there don't seem to be any barebones chuck bodies without on sale. Because that is what would make them actually interesting. Really how many sets of 50mm dovetail jaws do people need...