Discount / price reduction in the purchase contract for new construction with a general contractor

I am the PL for software projects. With some customers, we know that procurement still wants to negotiate something down. Therefore, one or the other percent is added on, knowing that procurement has to negotiate something down. Nevertheless, the price is designed very professionally.....

My question was aimed at whether this is also handled this way or similarly in this industry...

Our shell construction company has automatically granted a 3% discount so that we "are rewarded for prompt payment after acceptance" (his words).

At the last appointment, for example, we only pointed out that he is X thousand euros above the competitor offers. He also acknowledged this and then voluntarily gave us a position worth €1500 (with a total amount of €170,000) for free.

I also think that as a client one should remain fair and not insist on discounts - I prefer a serious offer over one reduced to the last cent where the contractor already has in mind where he could (secretly) save in order to still complete the project profitably.

I was able to push the price down by 5 TEU before UNT and even negotiated extra sockets and extra underfloor heating in the basement. I wrote a long email with many points and especially referenced another (really) existing offer from a competitor. But there was no more to get... However, I have the impression that the GU made it back on the change orders. So we did NOT have to supply any fill material on our construction site. That resulted in a credit of about 1.2 TEU. I then learned "by detours" or saw that the item was calculated in our offer at over 3.5 TEU. And this was also the case, for example, with the ladder and the step platforms for the chimney sweep and a few other small things. So in the end, I ended up paying for it again. That is initially frustrating. But we were very satisfied with the company and by now the annoyance has faded. We were to blame ourselves. If we had properly recorded the items in the construction services description from the beginning, this would not have happened.

Yes, my impression is that you can't get much. Basically, that's also OK, which means that the general contractor is making me a serious offer.

It would just be stupid if he has already planned an amount as bargaining chips and we don't even have that negotiation.