It's best in the long run to stick to a formula and that formula includes using the same materials and finishes over and over until something better or more cost-efficient comes along or design trends change.

Eventually his offer is above whatever formula the bank is using to determine value and they accept it. 

@Todd DexheimerI only deal with 2-4 unit properties since the profit formula/COC return is substantially better than commercial sized buildings and the resale is much easier so we are dealing in completely different markets,  I've sold 3 of them this year and the last one went for $10,000 more than asking in 1 day.

Is it a gut feel from experience or is there a formula to it? 

Don't think about the other guy and what he might pay, just what your formula says works for you.

Pay the bill yourself, then reimburse yourself by charging the tenants based on a formula.

@Jesus Moreno - check out the formula for RUBS - Ratio Utility Billing System and make sure your state statues/laws support it.

PVA primer always comes in white color and I always have it tinted with the the linen white formula because when it is white I can't tell whether or not I missed sections of the wall.

There is also some magic formula that is used, I believe the rehab loan would be around 70% of the after repair value (ARV). 

There is some voodoo in the formula so that you can't just game the system, but in general, if you post frequently, and people "vote" for you, your score will rise!