As the owner of 3 Laundromats I would charge at least the same as the local Laundromat or slightly more. You are providing a convenience to your customers and they do not have to drive or carry their clothes anywhere.
It intrigues me that Real Estate Investors will look at all of the numbers for their rental units and consider principle, interest, taxes, insurance, repairs, vacancy etc and then provide Laundry Equipment at a "fair" price without considering the costs involved.
Space- If that area wasn't a Laundry could you rent it to a tenant as additional storage space?
Utilities- All the normal ones- Power, water, sewer and hopefully gas. If you hot water and dryers are electric your costs will be higher.
Equipment- Washers, Dryers, water heater, additional door locks
Cleaning- The frequency will vary based on usage but it's has to be done. This includes cleaning up the spilled soap, cleaning the soap from the soap trays on the machines, checking the lint filters and picking up dryer sheets.
Repairs and Maintenance- First there needs to be a method for the customer to contact you or someone if there is a problem with a machine that needs to be fixed right away (water leak, door jam, washer didn't spin out) and a method to provide refunds. Or maybe the coin box is full and they got half of there money in.
Next is the repair. Local repair places may work on some of the models but most don't. They don't stock the parts or have experience with them. Even though they are not much different they just don't touch them. Trained service techs may not be in that area more than once per week. They normally work on a route system and cover a different area each day of the week.
And at some point there will be some vandalism. Normally they don't ever get any money but they may damage the machine trying or it could be "excessive use". People tend to feel they have to slam the doors on everybody else's Laundry Equipment.
Treat a Laundry in your building like a division of your business and charge accordingly. If your prices are too high it means less people will use the equipment and it will last longer and use less utilities. There is a reason people pay $1.69 for a drink at a "convenience store" when they can buy the same one at a grocery store for $0.39.
If you are looking for more information on repairs and other details check out LaundromatHowTo.com
And if you are considering a owning a Laundromat a great place to start is LaundromatHowTo.info
Ken