A link to next year's Ball.

http://www.royalcaledonianball.com/b.../ticket_prices

The price - £135

They do take things seriously though -

Dress

Part of the particular appeal of the Ball is that everyone attending is wearing traditional formal evening dress. The dress requirements are stated below in summary and in detail.
Please note that those not correctly dressed will be refused entry.
If you are unsure about any aspect of the dress code, please contact the Ball Secretary.
In summary

Ladies Full length dress
Gentleman Highland evening dress, or
Evening tails with white tie, or
Mess kit
No dinner jackets
So that's Prince Charlies out!

Regards

Chas