600m is a bit much. unless part of that 600m includes gifts to his wife like a megayacht. those can run anywhere from 100m to 1b+ even if you purchased one of the most exclusive properties in aspen especially for the wedding this would probably still only set you back 100m. then 1-2m in catering, 1-2m in prep work, 500k for staff, 1-2m for performers (make that 10-20m if the performers are celebrities), etc. you're still nowhere near 600m.
Switzerland