The property alone is worth a million but is generating an estimated $250k/ yr with the ability to add 3 units on site and acquire an additional 13 acres.

If he is offering you millions???

Many pest companies stated this was the worse infestation they had ever seen.Despite its condition, the property presented an attractive investment opportunity due to its below-market listing price.

Sounds like a million loud bangs.You might want to think about having it mounted over plywood with something between the plywood and the metal to cut the noise.

There are a million other things to consider trying to do STR in a condo.

The lower your price, the worst guests you attract, both in reviewing you and in doing damage to your furnishings. 

These areas tend to attract more reliable, long-term tenants who are usually more financially stable and take better care of the property.

I have 3 family apartment building and a SFH with 4 garages, 1 shed, and 4 outside designated parking spaces for sale for 1.75 million. 

It is not really apples to apples, but generally speaking the more money invested the further ahead you will be eventually in the future, just because your compounding base is higher, regardless of where the money comes from - ie, 4 300k properties are 1.2 million on property, which is double the 600k property.

The target customers are the unbanked and underbanked population, which is 30 million household in US.