Client needs Ubercart member sign up function, but there is error with edit/option_prices
If there is a problem it sounds like it's an issue with the menu tab links being generated for your nodes; node/test/edit/option_prices isn't a valid path, it should should be something like node/$nid/edit/option_prices.

The module enables that path if the UC Attributes module is enabled. It sounds like you've installed that module so I would substitute "test" with whatever product NID you're trying to test. Once you've confirmed it's working there, you can troubleshoot why your tab link is generating a bogus path.