Please Assist me in Understanding a "Cash-Out" Re-Fi...?

[Brandon Sturgill]

Can you please confirm my understanding of this strategy is accurate...so, I buy a cash flow property in the following manner:

Purchase Price: $100k (including all entrance costs aside from down pmt...)

Personal Cash $25k (down pmt. on 75%LTV loan)

Mortgage $75k

Amortization 30 yrs.

Interest Rate 5%

Monthly Payment $700

Rehab Costs $12k

Total Personal Cash on Deal $37k

ARV $130k (after rehab and 6 mos. seasoning)

then...

Re-Fi (estimates not including closing, current principal balance, etc...)

Mortgage $130k 

Amortization 30 yrs

Interest Rate 4.5%

Monthly Payment $800

Loan Balance $75k 

Cash at Closing $55k (mortgage - balance)

So, in this example I would be able to repay myself for the initial investment ($37k) and clear the difference to re-invest, etc...and the mortgage would hopefully be low enough to still cash flow?

This strategy seems to have infinitely different twists...things like varying rehab costs, origination fees, interest rates, amortization schedules, etc. And if the rent payment is not sufficient to cover the mortgage and have a reserve, I could lose money on a deal like this...