doesn't make sense

I think it is quite interesting how people are very hesitant to pay $10 to go to a party that provides alcohol and yet they are willing to pay $8 or more on 1 beer or 1 other alcoholic beverage. It doesn't make sense to me the decision behind those people. I mean, the amount of beverages they get served at the party for that $10 would cost over $50 at a bar... and yet people are more willing to pay that at a bar... it just doesnt make sense...