If you plan on funding the interior rehab from operating $, that's fine, but you will need to increase your R&M costs accordingly.  

I am very new to real estate investing and for my first deal I do not want to get any loans and want to completely finance with my own funds. 

@Michelle Elaine Fontan You could almost make 1.7% in a CD or bond fund without going into debt.

Any move in funds are cash or certified check only.  

I can then use those funds as a downpayment for my next property as the lender already did a financial background check..

Depending on what you are targeting you may even be able to work with a bank to have funding up to a specific limit available.Next you need to start networking with agents and other real estate investors in the area you want to invest in.

Also good to be in that habit for later on when you're sharing deals with others...If you're all cash buying and you have a reserve fund to backstop any expense on the house, then in practical terms you probably won't specifically earmark any of the monthly income "vacancy", but yes, it's still "in there".

Alternatively those funds can be rolled over into self-directed IRA (this would not be taxable event) and in turn purchase vacation rental or any other alternative investment. 

My uncle has a rental prop in an up & coming neighborhood that he wants to sell to fund his retirement.

Boston isn't because of the market, its because every idiot with funding thought they could all put new buildings up in Seaport and Fenway and there would always be plenty of people to fill them.