Definitely check in with @Joseph Chiofalo for Jumbo second home and investor loan products, we just had an unbeatable rate and appraisal waiver here on the coast. 

On a positive there are 15-20-30 year amortizations and increasing income qualifications including instant approval and AVM (no appraisal requirements) for very clean applicants, and creative documentation for self-employed borrowers or investors such as bank statements or even DSCR (usually up to 75%LTV) for investment properties. 

Only thing is she's about to order the appraisal. 

We lend at "the lesser of" cost vs As Completed Value, so we have you get your plans and specs together and then we give it to an appraiser that will appraise it "as completed".

Based off what I know from that area is you will be lucky to get it to appraise at 300k and you will be upside down.

It is based off the lesser of the appraised value or purchase price.

-your refinance will be dependent on your appraisal, and appraisals are inconsistent. 

PURCHASE PRICE AND MORTGAGE: I purchased the property for $270,000 put 25% down, and it appraised for $290,000.There is a complete identical property to mine directly behind my unit and it sold about a month ago for $280,000 the same day it was listed.

However I get a very nice cash flow on top of that the property appraised for 475k a few months ago. 

Also, even with no seasoning, it requires some rehab has been done to use the newly appraised value.