Last time I dealt with this as an engineer, I picked a vendor, procured a quote, discussed how license applies to our usage (which was somewhat of a corner case for the license), and forwarded it to procurement - few days later, we got the exact thing I asked for, on the conditions and for the price I agreed to with the vendor. Were there extra negotiations I'm not aware of done to close that deal? I don't know. If they were, they didn't have any impact I could observe from where I was sitting.
The real negotiating happened when you handed it off to procurement. Their job was to secure the contract with the terms and features you wanted, and it sounds like they did that. I think that's part of why so many programmers de-value the work of the back office (Legal, Finance, HR, etc). Good back-offices work in the background to get important shit done with minimal, if any, interference to the revenue-generating operations of the business.
It's pretty clear from the replies to my comment that you guys don't actually know what is involved in negotiating a B2B contract. The stuff the engineers are allowed to participate in is the layer of snow covering the tip of the iceberg.