Hello Patrick!
Thanks for bringing us your question. I'm happy to help as you make arrangements to visit
Walt Disney World Resort later this month.
The EU version of the Walt Disney World Resort website only gives the option to purchase a 2-Day ticket.
Ticket prices for a 2-Day 1 Park Per Day ticket range from €305.00/ticket for guests aged 3-9 and €314.00/ticket for ages 10+, up to €329.00/€339.00 depending on the start date selected. Prices will increase if you decide to upgrade to the Park Hopper Option during your visit.
Since you only want to visit
Magic Kingdom Park for a single day, you'll need to wait until you arrive stateside to make that purchase. You can do this in person at the ticket window of any theme park entrance or at the
Disney Ticket Center at Disney Springs. You may also be able to complete the purchase online using the
US version of the website once you've arrived. Prices are always subject to change, but there should be no difference in price if you purchase your date-based ticket online or in person with a Cast Member.
I took a look at the admission calendar for your travel dates and the prices range from are either $159/ticket for guests aged 3-9 and $164/ticket for guests aged 10+ or $169/ticket for 3-9 and $174/per ticket for guests 10+, depending on your date of visit. Wednesday, May 1st through Wednesday, May 3rd are all priced at the lowest end of this range, at the time of my writing. Keep in mind that 1 Day tickets for visits to a park other than Magic Kingdom Park may be priced lower and upgrading to a Park Hopper Option ticket will increase the ticket price across all dates. The aforementioned prices also do not include applicable tax.
I hope this was helpful Patrick. If we can answer any additional questions or offer guidance for your visit please come back and let us know. We're always happy to help!
Magic and memories,
Amy