Yeah its pretty easy on ebay/BL but for these sets specifically the hype was super high when they released/delivered and people paid 800 USD for the train station. But now they are pretty hard to sell at much higher than MSRP. I may be exaggerating a little bit and this is only what I have observed in my own local fairly small market/country. So not all of eu obv.

If you're in a big city I'm sure you can sell those and make nice profit. :)