You cannot make a general statement about the real estate transfer tax like that. In our case (existing property, i.e. house and land), we were able to agree with the sellers that they would pay the broker. Although this gave us less room to negotiate the price, having the commission included in the price was better for the financing than paying it explicitly on top of the purchase price. If we had to pay the commission ourselves, we would have had correspondingly less equity for the purchase price. The loan to be taken out would have been only slightly lower, but with a higher loan-to-value ratio and therefore a worse interest rate. If we had been able to pay €6,000 less on the purchase price for the amount of the commission, but the commission had been deducted from the equity, then the financing would have been approximately €6,000 more expensive because the interest rate was 0.2% higher (82.5% loan-to-value instead of just under 80%). The real estate transfer tax is therefore only €900 higher. Our seller didn't care whether he received the purchase price including the factored-in commission or if we paid the commission but a correspondingly lower purchase price. You have to calculate this for yourself; with our equity, we were exactly on the borderline between two loan-to-value tiers.