I'm assuming I'd have to get a local architect/engineer to stamp the plans.

You may also need to obtain a stamp from city hall.

This lower purchase price will lower the transaction taxes (stamp taxes) for the sale, which is based on the sale price.

If you're planning to go this route, you probably want to seek some form of legal advice from an attorney to make sure you're doing things correctly, make sure that everything is documented with some form of official proof (maybe sending via certified mail), and take pictures with date/time stamps, etc.My next thought was, "Are there any restrictions on STR in the HOA/municipality that the neighbor may be violating?"

I've been going back and forth on if I work with an architect or just an engineer who can stamp some drawings.

Perhaps part of your offer includes getting the legal status filed to permanent (need photos to advise, to file you need the manufacturer name, serial number (like a DMV tag in the water heater area usually), pay the fee, have county stamp it and it's recorded. 

I am also not a NC real estate agent, but my MLS has every edit to a listing recorded and time and date stamped. 

@Zach CarnerIf you sell the property for $308,000, you will likely end up with no profit when you factor in costs to sell(realtor commissions, title insurance, title costs, stamps, etc).Items to consider when selling a houseYou may pay around 7% to 9% of the value of the home in fees(Realtor Commissions, Title costs, Title Insurance, Stamps etc).The sale may also result in taxes(Federal taxes + State Taxes).You might be able to avoid taxes by doing a 1031 exchange or QOF Fund.You no longer have an asset that can potentially provide you cash-flow / appreciation.Do you think you can make up the 7% - 9% in fees + Taxes over time by buying another property?

I think they should have had people apply for Rental Assistance via standard Welfare Route with an expedite for the COVID problem.It's un-American to pawn off what are basicaly Welfare Cases on business owners.They didn't force McDonald's to provide 3 square meals a day for these people (for FREE).They get food Stamps for that, and McDonalds takes them in return for the food--and MAKES A PROFIT--off of them.No one wants to see more people go homeless (or hungry), but this is not the answer.

My buyer pays mine as the assignment contract states they will pay all costs to close - including stamps.