You will have the following expenses even before you buy that first house.Computer for your officePrinter for your OfficePhone system in placeGas tracking expense while checking out propertiesMileage tracking Phone expenses for business calls related to finding propertiesEducational courses and books to help you learn the businessOffice Supplies, and this is just a start.  

Having the air conditioner made no difference to the rent, which was the same that the previous tenants paid while supplying their own air conditioner.

Another general question :)For those that have serious wholesale businesses, in your opinion what percent of money do you spend for all your expenses, marketing, selling, equipment, office supplies, gas etc. etc., not including taxes.So if you do 20 deals at $5,000 profit each on average and make $100,000 in one year then xx% would go towards expenses.

The policy covers only legal liability for damages to the landlord’s property (covered losses include fire, smoke, explosion, water damage, backup or overflow of sewer, drain or sump, falling objects, riot, or civil commotion) up to $100,000.So when that tenants overflows the tub and nukes 3 bathrooms below it with water damage, that get's covered under their Tenant Liability Insurance to repair said damages.

They seemed to smoke in the house which is not great, but it is what it is.How would you approach it?

The odds that this is a possible solution are pretty slim but it may be worth a call to whoever supplies your water. 

We do have a problem here and it isn't demand - it is lack of supply, particularly at lower price points or really anything under the median.  

The duplex we went for and walked through , the carpets in one were destroyed and heavy smoke smell inside the unit.

When I got let go from that low paying dead end job at the hazardous polyurethane plant, I went back to school for Supply Chain Management/Logistics Management (transportation).

Add up all of the supplies you needed (Windex, paper towels, carpet cleaning solution, paint..)