Do you have to sign anything that pays them if you find something yourself? If not, then it's l not a horrible idea. If so, they may still bring value on the buy side.
I talked to one once and she said she would send me deals she had and if anything interested me we could talk about it. Seemed very informal and easy.
We ended up not doing anything as I had a business and was really looking for a bolt on at the time.
Ive had several friends use brokers to sell their businesses and they all appreciated the buy/sell expertise of the broker. Most felt like they ended up with a better deal than they anticipated.
As with any outside counsel, there are good and bad ones. So look for referrals and experience. Seem like tons of people have gotten into the franchise expertise business. The ones I know personally I would not do any business with.
If you know the type of business you are looking for, there are probably brokers that specialize in that market.