So to analyze the property I should use 885 as my property tax figures or is there a different number or formula to figure that out?

If you have developed your own metric use whatever you are most comfortable with and use the same formula every time so 75% for a 4-plex, 66% for a triplex, 50% for a duplex.

Because appraisals are arrived at by formula vs. form.

@Shelly Shanks For buy and hold the formula is relatively simpleAnnually:(Monthly rent x 12)- property taxes - insurance -property management fees - HOA fees if applicable - budgeted maintenance and repairs- expected vacancy - loan payments.This will give you your annual cash flow. 

The basic formula is ARV - Needed repairs - 3-5k for assignment fee = offerexample $45,000 - $10,000(repairs) - $5,000 (fee) = $30,000(offer)Hope this helps

I buy in south Dallas TX and it fits the formula perfect. 

I have read a basic formula ...and evaluate to see if you are happy with the numbers but...1) Buy at 40%-60% of the planned ARV. 2) Rehab should cost you between 10-30% of the ARV. 3) All money in to the deal should not be more than 70-80% of the ARV. 

What would become your new measuring points in this type of area or would you keep the same formula for these type areas as for all of your deals?

Price =NOI/cap rate is the accepted formula.

@Jay Hinrichs Do you have a formula you use on your projects for a percentage you'll pay for lot in comparison to construction or market value of home?