At the end of the day the PM business is a service business and being unable to communicate with the PM for up to 2 days won’t cut it.

Your entity structure is no efficient and you could have filed one return.

We self manage.We've hesitated to list anywhere else mainly because we communicate with guests exclusively through AirBnB.

Full stop.Unique style, ample amenities, good location, great photos, solid communication, etc etc. 

The reason why that approach is effective is that those communication channels will be less saturated with competition, and also attract more actively interested people.

Additionally, a larger property like this is valued based on the actual cash flow, not sales comps, so you have the ability to force appreciation faster with efficient management.Adding the a 5-10 unit may also increase the amount of time you spend getting you closer to the 'Real Estate Professional' status for tax purposes opening up room for offsetting some W-2 income on taxes.  

Knowing a ball park figure can help me pick a price I will see if the homeowner will accept because there is alot of needed work)What kind of project planning should I do to make this an efficient project and reduce cost but keep quality?

Or is there a more efficient method to do this?

The only real differentiation can be in operations, and operational efficiencies.  

We bought Ocean Walk Shoppes out of bankruptcy cash, no lender wanted to to play here cost efficiently, about three years ago.