When buying a house, should you follow the numbers exclusively?

[William Pope]

I have been looking at a 3-family house but when I run the numbers, the cash flow is in the red something like $230. Are there times when the numbers aren't showing the true value of a house? I asked him if he'd be willing to negotiate the price and he said he already had a full-price offer. I find this hard to believe. If he really did, why would he bother with me? I'm trying to find comps but having a time of it. House is in Passiac, NJ

[Joseph Gozlan]

@William Pope there are fools born every day so don't be surprised if someone outbids you these days. 

Stick to your numbers and make sure you build enough reserves because life happens...