The tricky answer is, it depends.
Making maple syrup is interesting in that getting started is easy. You can typically use inexpensive or homemade equipment and if you have access to lots of firewood, then boiling is easy. The reduction of sap to syrup is 40:1, so collecting about 40 gallons of sap will leave you with a personal supply of syrup for the year. Beyond that is where the variables come in.
The cost of spiles, hosing, and collection containers for tapping is cheap. Stainless evaporation pans are expensive (roughly $1K new). My goal for this year is to collect about 400 gallons of sap, which means I'll burn through about 2 cords of firewood (that's a significant amount but you would never use propane because of the sheer cost). So do you buy your firewood or cut it yourself? That alone is a lot of work. Many (no, all) large operations use reverse osmosis filtering systems to concentrate the sugar content of the sap before boiling. This can cut your evaporation time (and fuel needed) in half, which is also significant. You can buy a ready-to-go RO system for drinking water off Amazon for a couple hundred dollars but the membrane capacity will be small and slow you down. An ideal RO system for my current scale is in the $3K range.
The weather plays a huge role in sap collection as you need below freezing temps at night and above freezing temps during the day for the sap to flow. This limits the season to just about a month. Today I'm doing absolutely nothing as the high for the past two days has been 25F and all my taps are frozen. Non-cooperative weather can shorten the season and limit how much sap you can collect.
So my 400 gallon goal should yield me about 10 gallons of syrup under ideal conditions. I bottle the syrup into 12oz bottles that could sell for about $15 each. Roughly 100 bottles means a potential gross revenue of ~$1500; not great considering the cost of the bottles and my labor alone have nearly wiped that out.
I would estimate that a sugarbush of at least 150 trees, a professional RO system and evaporator, plus no additional labor costs could start to see a small profit if you either acquired your equipment for free or amortized the cost over at least 5 seasons. The requirements for bottling for retail are relatively easy where I'm located so you would just need to find a viable market for sale. The alternative is to collect and RO sap which you can then sell to an industrial processor for a reasonable price, which could move your profitability timetable up as your equipment and labor costs would be roughly cut in half.
But that's just some back of the envelope calculations. I don't know any local producers who do it for profit. The real key to turning this into a business is owning a viable and mature sugarbush. Anyone who has 50 or more sugar maple trees on their property in close proximity to one another and is not tapping them has no idea what a fantastic resource they are sitting on.