Social event calculator

Burger: 18.50 CHF, after discount 17.56 CHF
French Fries: 6.50 CHF, after discount 6.18 CHF
Total (before discount): 25.00 CHF, after discount 23.74 CHF

Item	Base quantity	CHF	Qty	Total
Coca Cola	6×1.25l	2.00	13	26.0
Water (ohni gas)	6×1.5l	1.15	15	17.3
Water (mit gas)	6×1.5l	0.65	10	6.5
Plastic cutlery	60pcs (Knife + Fork)	13.00	1	13.0
Beer cups	100×300 ml	10.00	1	10.0
Beer	6×5l keg	19.30	6	115.8
Total				188.6

Beer stock: 6 × 5l kegs = 30 litres → ~100 beers at 300 ml per cup
Stock cost: 115.80 CHF (included in Drinks + Other)

First beer per attendee is part of the menu — covered by the entry fee.
Every additional beer is sold at 3 CHF, which recovers the cost of further consumption.

Unsold beers stay as unrecovered cost in the total.