How many cases of wine should I buy for a conference wine reception for

[louise1885]

approx. 30 people? If a case of wine contains 12 bottles then by my guessing, two cases would be sufficient to provide each person with roughly four glasses each with some to spare. I'm keen to do this as cheaply as possible due to budget constrictions but also, don't want to run out of wine! Any suggestions are greatly appreciated. Thanks!