I completely tore out the walls in a room as all the drains from the upstairs bathroom were leaking in the walls. 

PLUS, All new gray wood laminate flooring, bathrooms with Italian carrera-like tile, real wood double-sink vanities with marble and granite tops, White-Quartz counter tops & 6" back-splash in kitchen with White shaker self-closing cabinets, nickel brushed hardware and stainless steel appliances.

-I'll look into now.From the owners description, "the roof is new in 2019 and everything else is newer such as the furnaces, central air, water heater, kitchen, appliances, and bathrooms." 

THE DEAL (this is where the SWAT team comes in):So the house I'm looking at is a single-story, single-family home in a B/B+ neigborhood with 4 bedrooms, 2 bathrooms, and 1700 square feet. 

Depends what the intent of the property is - if you are going to flip it, will go on your balance sheet as inventory and any costs associated with improving or rehabbing the property will be capitalized to the cost basis of the house (roof, walls, bathroom, etc).

Although it is possible they want to use the bathroom, freshen up, change clothes, etc

Purchase price: $45,000 Cash invested: $9,800 Wholesale property, 5 bedrooms, 2 bathrooms.

lying realtors and bad existing tenants aside, 1 bathroom in a 3 bedroom house is a limiting factor if your hopes were to attract better tenants then the ones in there.

Have you allocated enough monthly CapEx for HVAC, paint, carpet, bathrooms, plumbing, appliances, etc?  

HVAC, roof, bathroom remodels, square footage additions, etc.