Nearly all Dutch listings are priced kosten koper, a phrase that is easy to skim past until the closing paperwork arrives and the total is well above the asking price. First-time buyers who have budgeted only for the purchase itself tend to meet that gap late, when there is little room to adjust.
Kosten koper (buyer's costs) refers to the closing costs a buyer pays on top of the purchase price, and it's the default in nearly all Dutch home sales. The biggest single item is transfer tax (overdrachtsbelasting) — 2% of the purchase price for a primary residence, unless the under-35 starter exemption applies. On top of that: notary fees for the transfer and mortgage deeds, a valuation report (taxatie) that lenders require, mortgage advice fees if you use an adviser, and a bank guarantee (bankgarantie) — a deposit, commonly around 10% of the purchase price, pledged as security when you sign the purchase agreement, which costs a percentage fee if arranged through your bank rather than paid in cash. If you hire a buyer's agent (aankoopmakelaar), that's an extra optional cost. People typically budget around 5–6% of the purchase price for the closing-cost items themselves (separate from the guarantee deposit, which you get back), on top of any down payment.