Calculating APR into ROI

[Nancy Stark]

If you always have carrying cost at 2.75% how do you calculate deals?

For example, let's say you have $200K cash-out from refi at 2.75%, and you BRRRR at property, how do you calculate the ROI?

ie,

      $200K at 2.75% for 30 yrs = $458/mo carrying cost

      $130K total cost of property (including rehab) 

$150k ARV

$105K LTV refi @ 4.5% - assuming 70% LTV

                 = $25K left in deal (paying 2.75% interest) = ~$57/mo carrying cost

Do I add the $57/mo into my NOI to determine if it's a good ROI?

And how should I calculate the $458/mo that I will be continuing to pay? I plan on building a BRRRR portfolio but now I have trouble analyzing these properties.