Let's do a cost benefit analysis:
1. Cost of travel and accommodations from Europe to Duke... I dunno, like $2,000?
2. Potential upside of getting into top choice school? $20k/yr stipend + $10k/year free tuition + $5k misc X 5 years = $175,000
3. Peace of mind from knowing you interviewed in the best possible way: Priceless?
No brainer for me, just go. This is your future. Time and money are of little to no consequence.