To celebrate birthday economically, you need to have at least some financial budget. Proceeding from it and from their own wishes, think of how many people you would like to see at the festival. Then recall their eating habits to be acceptable to all menu. If you want to celebrate a birthday at home, there should be a minimum of three dishes: an appetizer (usually a light salad), main course and a dessert, which is normally the cake.
If the budget is tight, and on the street wonderful weather, buy sausages, some vegetables and bread for sandwiches, with whom you can arrange a picnic. Bring warm bedding and some blankets to cover them invited, if it becomes cool. We'll just tell the guests about the idea of the walk in advance, because it is likely that someone may not be ready to leave the city.
Not to wrestle with the variety of drinks, invite each of them to bring a bottle of their favorite wine, etc. And not to put friends in an awkward position, ask for a symbolic gift that would not be burdensome for their wallets (greeting poster, shared bouquet of flowers, a souvenir, a song or a poem, etc.). However, this option is acceptable only if all your guests are old friends.
To make the holiday memorable for a long time and will not turn in the normal absorption of food, in advance take care of the entertainment. Create 4-6 games that would require the least financial cost to the details. Due to the special brochures that you can find in any bookstore, and search online, you will easily be able to make a program of entertainment for the evening. Self-organization of the holiday will allow you to spend your birthday the way you want, and save the money you would spend on the invitation of professional Toastmasters.