Every job we bid has specifications. Quite often, specific light fixtures are called for, or they want you to do more than 'code minimum.'
As an example, one job I am currently doing specifies steel fittings with plastic bushings - rather than the usual die-cast zinc. Some of the wire sizes called out are also larger than 310.16 would require.

So- here's the question:

Assume you've lost a bid. Do you re-visit the job to verify the 'cheap guy' is meeting the requirements of the job? Or, do you leave it to the customer to enforce his plans?