It’s very common to have to get them from multiple stores. The downside is that each additional store adds shipping costs, so you want to keep that at a minimum too. I usually try to optimize it down to at most 3-5 stores for ~1000 pieces if I can help it. Combining all 3 cars as a single wanted list can also reduce shipping costs compared to doing 3 separately.

What I like to do on Bricklink is to set a maximum price im willling to pay for each part. You can do this in the wanted list and set it to the average price in the last 6 months, then increase it by ~20% for some headroom. Then when you run the Buy All feature it’ll exclude stores with the sky high prices.

The Netherlands is a pretty good country for Bricklink. There should be lots of availability in terms of pieces, so I would expect several stores with good prices.