I would buy something closer to turn key if you can, even if you pay up, because it will reduce the work you have to do and figure out as a new large-scale investor.

I know they say you get what you pay for but I am impressed with this STR PM, and I use Steesa and Innago. 

Some PMC's will charge a lower percentage fee, but will charge it whether tenant paying or not.

- If i Sell , as this was my 1st house and lived in 4 years, do i need to pay capital gain tax ?             

For example I would rather buy a property for a $100k discount that may have negative cash flow of $500/mo month for 3 years than pay market value for a property that cash flows $200/mo.

If you have a great-paying, long-term tenant, a small discount can actually save you money in the long run.

Or, if you pay 20k over list price on a property that is 50k underpriced, you still got a hell of a deal.

Pay your attorney and your CPA for a customized advice. 

If they pay the new amount on time no problem.

@Aaron Bard- plenty of  lenders  offer  DCSR loans ...contact a  few  for  quotes ...also - dont  pay  any  lenders  at the beginning of the process