What are the $$ costs in an Espresso enterprise?

You cannot overestimate the importance of a really good location. Be prepared to spend the extra $$ to get the busiest traffic spot you can. Close proximity to a university, college, or large office complex are usually good spots. The rent for this location along with your utilities is your basic overhead cost.

Your espresso machine will be the backbone of your business, so if you're going to cut costs, do it somewhere else. This is the one piece of equipment you can't function without, so buy a reliable machine from a vendor with local references and a proven track record. A quality two-group starts around $5500 and goes up from there depending on features. Don't buy a used machine unless you know where it came from, if it was used for less than a year, and that it has a warranty.

In most municipalities you will need a three-compartment sink, a separate hand sink, mop sink, S/S worktable, refrigerators, a display case for food items or a sneeze-guard protected area. If you are planning to cook anything, in addition to the cooking equipment you will probably need an exhaust hood over it. All of these items will probably need to be commercial grade and NSF approved.
You will also probably be required to cover the walls and ceiling areas where any prep work is to be done with an easily cleaned material such as FRP board. You will also need to cover the floors with an easily cleaned material and all counter bases should be coved. Prep and work areas should be covered with S/S or commercial grade laminate.
Finally, if you are going to have seating you should pay close attention to the construction of the chairs in particular. Commercial chairs are heavily reinforced to accommodate very large customers. Good ones come with a 5 year commercial warranty, so if your chair breaks when someone sits in it, you're covered.

Most restaurants and foodservice ventures lump these two figures together. Ideally, you want to keep the combined cost to less than half of the total operating budget. If you are selling a lot of espresso drinks, this shouldn't be too difficult as the average cost is only around 35 cents per cup. This is why a reliable espresso machine is so important, because most of your profits will come from it.

You'll probably want to budget something for advertising, but don't go overboard. Every advertising salesperson in the state will try and convince you that unless you place an ad with their magazine, newspaper, phone book, etc., you won't sell a single cappuccino... but, they're just trying to sell you something. Test the waters a little first, and if you think they might help you reach your target market, go for it.
You might want to think about selling your own advertising. Coffee lovers like to wear t-shirts and drink from cups that sport logos from their favorite java joint, so let them pay to advertise for you! And don't forget that you can sell your own privately labeled coffee too. Talk to your coffee roaster.
Of course, you will also have to budget for insurance, worker's comp, state, local and federal taxes, operating fees, permits, an accountant or bookkeeper, and anyone we forgot to mention.