The most asked question from beginners...
Before you have mentally made the plunge to go forward with any business - you need to run some numbers. My calculations will be for a medium/large store with about 75 total machines (Washers and Dryers) and about 2700 - 3000 sq. feet of store space.
In the laundry business you will have two major upfront costs. If you're launching a brand new location (or refurbishing an existing one for that matter) you will have Construction Costs. The Construction costs for a store this size will probably be around 100k - 200k. Our last venture was in a strip mall and was on the higher end of this range. The major pieces of these costs will include, electrical updates, plumbing and general carpentry. You should get a few contractors (to shop prices) and expect no matter what quote you get to end up about 20k higher based on unexpected code/inspector requirements. You should try to add limits to your contractors contract so they don't go overboard.
Another major cost will obviously be the machinery. You need to talk to many vendors and make sure your Representative is knowledgeable and very responsive. We fired a few companies before deciding on our company. The selection was largely due to the diligence of our Representative. An experienced and knowledgeable Rep can act as more a consultant working on your behalf rather than just as a salesman. Research the maintenance capabilities of your vendor as well as the Financing plans (interest rates etc.) they offer also. A brand new machine mix for the 75 machine range will be 200k - 250k. If you have good enough credit and financing the whole note of the machinery can be financed.
There are other start up fees also such as: incorporation, lawyer, lease negotiations and legal review, Security deposit for landlord etc. These are smaller fees compared to the bigger chunks detailed above, but you need capital for these also.
If you're buying your location for your laundromat (which is a whole other topic of discussion on the pluses and minuses) you will obviously have another large note to contend with. Having to not deal with a landlord is a great plus but we'll get into that later.
These are broad brush strokes and ballparks of start up costs for the size store illustrated above. I welcome feedback and more in depth discussion on any of the subjects above.