i realize by the price ($79.00) and quality of the original no ones really tried to copy the SM57 (MXL, SP, etc.) ...but has any budget mic company successfully (or tried) to copy the ($299.00) Senn. 421?
Not really. But you might be able to score a used Beyerdynamic. Scour the ebay scene for something along the lines of a 201, m69 or m88.
I think you'll notice a lot of similarities between the Beyers and the Sennies, in general . . . and they're very close in quality, also. You'd be a lot better off going that route, rather than with a cheapo copy.