Triplex valuation

[Jon S.]

How does one evaluate the value of a triplex using income? 

If for example, rental income is expected to be $3000, how does that effect the valuation of the triplex property?

I know how to analyze the cash flow, the Cash on Cash return, etc. I'm really wondering how to analyze the price one should pay in order to get a triplex with that rental income. Is there a standard formula? 

Thanks