We bought a used kitchen for our house, as we had done for all our previous apartments before. First, we thought roughly about what should be included, what shape, etc., and then looked on classifieds. The selection there is huge. Many people sell almost new kitchens for a fraction of the original price.
Ours is from Nobilia, cost 6000€. For that, we got about 12 linear meters of kitchen, including appliances.
We then arranged it in the room as we wanted. Above that, a new countertop (oak glued laminated timber, 700€) and done. A carpenter took down and reassembled the kitchen together with me. One cabinet had to be modified a bit, and some creativity was required here and there. Here is the price list:
Kitchen: 6000€
Renting a van: 69€
Carpenter wages: 800€
Countertop: 700€
Miscellaneous: 100€
Total: 7669€
And there were still cabinets left over for the utility room and my workshop. I would do it this way again anytime, let the others pay the crazy prices.
An acquaintance of mine used to be a salesperson in a kitchen studio and said that it is practically impossible to get a "fair" price there. The margins are huge. Depending on the customer, different price lists are applied, and any negotiation is just a show so that customers go home feeling good.