No question that this is going to be expensive, but there are some things you can do to keep the cost more moderate. You might begin by stocking only the basic liquors. And, in any case, you do not need to purchase the premium brands at their whopping premium prices. If you really like them though, purchase enough for you and perhaps the one or two guests that can tell the difference, most can't tell and don't care.
The Basics
These are a must to have in your bar. With them, you can mix many a fine drink.
Vodka Gin Rum Whiskey Tequila
These will go fast so stock a few bottles of each in reserve.
Beyond Basic Liquors
These liquors are secondary to the basic but some people will ask for them, so it's up to you whether to stock them or not.
Scotch Brandy Cognac Irish Whiskey Jagermeister Rumplemintz
If you don't drink scotch or cognac yourself, don't go for the expensive stuff. They cost an exorbitant amount and even then, tastes differ among even premium brands, so chances are you won't be pleasing anyone anyway.
Liqueurs and Cordials
Blue Curacao Midori Cointreau Grand Marnier Triple Sec Kahlua Bailey's Irish Cream Peach Tree Puckers Amaretto Chambord Frangellico Crme de Menthe Crme de Cacao Anisette Vermouth
In the interest of saving money you can find most of these under the brand name of Mr. Boston for less than the well known brands of each. These are very nice to keep in your bar because they can be mixed to make so many different drinks. They last a long time because you use so little per drink and they won't go bad on you.
Non-Alcoholic Drinks and Mixers
Grenadine Sour Mix Lime Juice Cola Diet Cola Red Bull Orange Juice Pineapple Juice Cranberry Juice Grapefruit Juice Tomato Juice Sprite or 7up Soda Tonic Ginger Ale Cream Milk.
Buy the 8oz cans of juice so they won't spoil unless you are throwing a big bash and expect a heavy volume of drinks to be served. The milk and cream will have to be purchased as needed.
Garnishes and Condiments
Cherries Olives Cocktail onions Bitters Worcester sauce Tabasco sauce Salt Pepper Lemons Sugar Limes Oranges Picks and stirs
Most of these can be stored for long periods in either the refrigerator or on a shelf or cabinet behind the bar. The fresh fruits will have to be replenished as used.
Now you are ready for a party. Call some friends in and show them your finely stocked bar and what a fine bartender you are. They may never leave.
For more information on basement bar design or to get your bar plans check out Bar Plans Online.