Remember, 1 Euro = 1.5 dollar.

Rental - 8 hours
Dinner in the Sky (table + crane + insurance + logistic & staff) € 7.900 / day
Transport (table + crane) € 750

Options
Lights 250 €*
Heating (8*2.000 watts) 750 €**
Customisation (underneath banner, seats stickers) 1.250 €
Location Package (location research, negotiation & renting) between 1.500 € & 2.500 €

Extra hour (maximum 4) 265 €
Flying podium 2.850 €
Photo Package (photographer & website) 700 €
Welcome Package (desk, hostess, wc) 525 €
Catering: on request (this mean food's not included)

Here's the linkypoo

So I'd say $25,000 for a dinner party isn't that far off an estimate.