Preparing Turkey is one of my specialties.
Turkey, veggies and other food can be bought cheaply at the mercado. And drinks can be bought for a democratic price at MAKRO.
If an expat is willing to borrow his big roofterrace or lives in a building where there's a communal party room then that would be an advantage. Chairs and tables can be rented for little money.
Nice paper napkins, tablecloths and decoration can be bougt at a democratic price in the Calle Capon área.
I am prepared to pay 15 lucas. Nada mas.