Uhhh, you didnt do your homework properly in my opinion .

You keep mentioning United so I assume you are used to their award flights which come without Fuel Surcharge. This is a completely different story with M&M. In most cases you will pay something in the range of 300-600 US$ for a transatlantic award flight. Be very careful on what airline and how many stops you choose for your award flights (not sure what is the current fee deal with spending M&M miles on united)

The United Explorer Card currently gives you 50k miles after 3k spent, fee waived in first year.

The meilenschnaeppchen are btw also available in Y for 30k.