I'm too skeptical for some things thought.... 1st I have no numbers in my hands since the seller never involved in renting the apts , 2nd Do you think I'm exposed to a bigger risk since it is the beginning and I will not have a steady cash flow out of short-term renting? 

Fined motivated seller that would belling to sell you a small MFR with no money down.you will need to find someone that is a tired landlord and they would want to receive income but not be involved in the day to day management of the property / tenants. 

I need to come up with deal that is very enticing to seller, and to me of course. here was my plan make a deal where he sells both of them to me with 5 year purchase plan however I would purchase 1 first in 3 years with the 2nd one 2 years after.

While flipping to other investors or home buyers who need seller financing is not sexy, it is profitable and can be done in volume.

Sellers actually leave me a message :)

Based on the demand in the area and existing rents, I used $900 a door

That is not 7% of the profit but 7% of the total amount given to the seller.

Would discuss with a couple of realtors and get their opinions on location/demand for specs first.

Hi @Natasha Richardson,I wish I could answer your question more directly but it all depends on the location, quality of property, recent sales activity, supply and demand.

I'm currently working with a seller (wholesaling my contract for her house)  and she informed that her mother's house was just bought by an investor.