Broker commission: $88,900 Legal fees: $18,297 This equates to ~18% of total sale price. Most people don't realize how much get eaten up in deal/closing costs. Congrats to him for the successful exit. Reading his blog post over the years should be eye opening to anyone just how hard starting/running a business is.
That's not how it works, though. Without a broker you may not find a buyer at all. If you do, you might not know how to price the business. Even if you could find the same buyer at the same price, they might be uncomfortable dealing with someone who doesn't know how to navigate the sale of a business and end up backing out.
For some very small web businesses, you can usually get away with a broker. Nobody is dropping $90K on a broker to sell their $50K side project on one of those business buy/sell websites, obviously. However, once you get into the territory of niche hardware businesses, it's very helpful to have someone on your side who can help navigate the situation.