I have a quote from a company. I would like to get competing quotes. Is it unethical to send the quotes from the first company, with names and costs redacted, to another one and ask for a competing quote?
In most cases it would be bad form. There is potentially work that goes into the quote beyond just figuring out pricing. Assuming you aren't going to the first company with catalog numbers in your quote request, they put work into determining you need A, B, and C to meet your needs so providing the quote to a competitor is essentially supplying free labor to the competitor.
Additionally work goes into structuring business documents like quotes (especially if you are talking about detailed quotes for services). By providing an example of a competitor's document you are giving them an advantage in learning from the competition.
Well, you can send the quote(-ed amounts), but be sure to leave out information that can lead anyone to identify the organization providing the first quote.
However, if you're providing the reference to the amounts, you are essentially allowing them to match those numbers (should the second numbers been actually lower). I'd suggest, ask for quote individually and then have the comparison done yourself.
It involved a lot of back-and-forth to get them to understand our needs
well, maybe the requirements need more clarity then. Learn from the interaction with the first vendor, and refine the requirement in a way that successive interactions with other vendors do not need that much back-and-forth communication. There will be a certain amount of discussion needed anyway, that is unavoidable, but a well-formulated and specific requirement can help that keeping at minimal.
If it doesn't have a non disclosure appended to it somewhere then it should be ok, but it's not the normal way for many excellent reasons.
Primarily it's essentially useless to ask them to quote based on what another company sent rather than your actual needs/blueprints whatever and usually a site visit as well for cabling with any sort of special needs.
I've done it and would never quote without a site visit even for normal cabling. I'd think it was spam if I was sent someone elses quote. It tells me nothing except materials and time.
I would never base my quote on another’s quote:
they may have missed something,
they may have a part or similar that they can supply cheap,
So, also considering most quotes that I have asked for have a clause in them along the lines of “ only valid for person xxx and for 1 month from the date above” then you may not have the right to share quotes.