How to value a Fast-Food Franchise?

Hello guys. I have been recently looking at buying a business for the past half year. I have met many brokers, and everyone seems to use a different formula.

Currently I believe to have found a prosperous national fast food franchise located in the food court of my local mall. Now I am trying to calculate a rough value to make an offer, to finally reach the due diligence stage.

My last broker who represented me, I am not sure if he was right or wrong. He had me scratching my head a few times. He said to calculate the value of the business you take the NET PROFIT
(ie. after expenses, taxes) and use a multiplier of 1.78. And to add in assets and you come out with the rough value of the business.

I have come across other brokers who state it is the CASH FLOW (ie. expenses but NOT taxes) and then use the multiplier to calculate the value.

The business right now has a net profit of 200k a year, and a gross profit of 896k a year. The seller is asking 650 for his price. And the broker representing him was adamant that he is looking for a multiplier of 3. Which I had talked to my old broker and he stated the current multiplier for the market is right around 2. So I am lost and not sure which way to go, can anyone shed light?