Marking up invoices is unethical in my opinion, but it's not illegal and I don't know if your contract allows the PM to do that- it's very likely that they have every right to do so. 

Does allow for me to save quickly.

@Kristee BadetHouse hacking involves living in a multi-unit property and renting out others, potentially offsetting mortgage costs and allowing savings for a personal home.

Seems like we could be negligent if we allow self-guided tours and someone leaves a window or the back door unlocked and comes back to occupy or destroy the property later.  

We think it’s important as it allows us to check for Non-Sufficient Funds (NSF) issues and to determine if an applicant is living paycheck-to-paycheck.

I'd encourage you personally to either consider a strategy that allows you to add value quickly and get out quickly (a Flip or BRRRR) if the HELOC is your current only/best option for cash, and/or to simply save up.

House hacking (buying a multi-family property and renting out units while living in one) allows you to cover or reduce your living expenses while building equity.

Some surrounding suburbs still allow it, but the only way to have a new STR approved in Waco city limits is if it's in multifamily or commercial zoning.

To that end, I made a Google sheets document with every hospital system in GA along with the following data:CityZip CodeRentometer 2/X   (what a 2 BR, any bath) goes for on Rentometer)RentRentometer 3/1+ Rent (what a # BR, 1.5+ bath) goes for on Rentometer)"Minutes to home"  (how far a drive it is for us)"Staffed Beds"  (measure of how big a hospital is)"Total Discharges" (a different measure of hospital size)"Patient Days"  (yet another different measure of hospital size)"Gross Patient Revenue ($000)" (you guessed it, hospital size)Map Searches & Housing Requests (this and everything below was from FF.com stats page)Furnishedfinder.com Page ViewsTotal RoomsPrivate Rooms % UnitsHotels% Whole Place > 2500 %Whole Place > 2k < 2.5k %Whole Place > 1.5k < 2k %Room > 1500 %Room > 1k < 1.5k Page view per roomThis allowed us to narrow our search to hospital systems near us (less than 2 hours) in a less competitive market (higher page views per room advertised on FF.com) with a significant % of units being rented on FF.com at higher rents (more $). 

ADUs are a great idea and California (and most of the West Coast) is on the forefront of the most allowance and options for them, but I would think about your long-term value also.