Working the numbers

[Melissa W.]

Hello,

My talent is finding good deals and rehabbing a property to sell quickly.  My questions are to the experienced flippers, (1) How do you determine fixed costs such as Ins., utilities & property taxes?, (2) How do you determine your repair costs, and (3) How do you determine holding costs?

These are items on my spread sheet to bring to my lenders to show them that it is a good deal.  

Does anybody know what the average costs are in Southern California.  Everything in this state is much higher than other states.

What I have been doing so far is estmating what I pay personally for my utilities, water, gas, property taxes, and insurance.  I also asked a few friends what they pay to compare.  The area I live in is a higher end nieghborhood than the area I am flipping in.  Is there a more efficient way I can be working the numbers?

Thank you.

Melissa