How do I value this business we might buy?

We are considering buying a golf cart repair business. How do I figure out what I should pay for it? It makes $100k a year right now for the owner. That’s salary and profit combined. It has three trucks (it’s a mobile service) and some inventory. The trucks and inventory supposedly are worth $60k. I think that’s a little high on the estimate.

I know very little about buying businesses. I tried to google info on that type of business, but didn’t get anywhere. A friend if mine said in pest control you get a truck and the regular customers for usually the gross income amount.

I see small restaurants for sale and they all seem to ask for a little less than double the gross income.