Can I look up a large list of cards on MagicCardMarket.eu?
Thanks to JonTheMon in chat I've been able to find out how to get to this feature. It's a registration-only feature hidden behind another feature.

The basic steps are: register &rarr; set up a wants list &rarr; via that wants list, enter the shopping wizard.

The detailed steps


Register an account. You can't access the feature anonymously yet.
Once your account is registered and verified, mouse over the Buying menu and pick My Wants from the dropdown.
Once on the Wants screen you'll see nothing other than the option to create a "new list" with a single input. This input will be used to name the list itself:



Enter the name of your list here and hit the plus button. In my case I named the list after the deck I was buying cards for, and called it "hapatra wants". You can set up other Want lists later, or delete them.
Once your list is created you'll see the screen below. Hit Add Deck List for mass adding:


Enter your cards in the 1x Card name format and hit the plus when you want to add them:


You'll see a confirmation below, and can hit the small "back to your wants list" button at the bottom:


Now that your wants list is set up, you can hit Shopping Wizard:




From the shopping list you can configure how you want to search, and it'll produce one or more batches of cards from sellers matching your criteria.