Help understanding the BRRRR method; sample analysis

[Laura C.]

I am a new investor looking for my first deal and came across this duplex that I thought might work great with the BRRRR method, but could use some input on my analysis. I also want to make sure I'm understanding the method correctly.

Property is a duplex with a 4 bed/2 bath unit & 3 bed/2 bath unit in a B- neighborhood in the Inland Empire

Proposed Purchase price: $315k

Rehab costs: 40K

Predicted ARV: 425k (currently a similar unit on the same street with fewer bedrooms selling for 430k)

I have analyzed the deal completely using the BRRRR calculator, but have some questions after doing that:

1) What are holding costs . . . the mortgage before I rent it, or is there more? 

2) How exactly do I get my money back out? Don't I still need a down payment if I go with the traditional financing for the refinance? 

3) With the scenario above, I was planning to borrow 125k (private money) for the down payment (initial purchase), closing costs, holding costs, and rehab costs. Then if I refinance in 12-18 months at 425k at 70% LTV that would be 297,500. Does this mean I can pull the difference between 425k and 297,500 out as cash? (That would be $127,500) I'm confused how to calculate the amount of cash I "get back" in the deal.

4) Lastly, if the amount I can pull out is 127,500 that's barely enough to pay back my private money investor with interest, but I would have an income producing property at roughly $250 per door. Is that worth it? 

Thank you in advance for you input. I appreciate it! 

Laura