Each 750 ml bottle contains 25.36 oz, which equates to 16.91 drinks per bottle based on a 1.5 oz serving size. Assuming the average guest has 3 drinks, you will need about 600 drinks to serve. 600/16.71 = 35.49 bottles. You will need 36 bottles of Crown.
Obviously there are those that won't drink and others, such as myself, who would have 5-6.
At $31.95 per bottle, it will cost $1,150.
[This message has been edited by Old School Wrecking Crew (edited 1/4/2010 2:18p).]