When it comes to selling wooden craft items at shows I have found that I do pretty well at growing pumpkins and selling them here on the farm...
Horse boarding is not bad if you can convince people that they should pay their bill. House rentals tend to fall in the same category.
One nice thing about the woodworking hobby is that it is often a lot less costly than antique tractors as a hobby.
I have heard of boats as being a hole in the water into which you pour money... The antique tractor hobby and owning horses are both a lot like that.
My other time consuming hobby is genealogy. Traveling around the country to stomp through overgrown cemeteries isn't too expensive but may soon require a block of time in England and Scotland, mostly northern England. I always told myself that I wouldn't go until we could drive there but that may not work out.
I once had a renter that had almost free access to pallet wood (new stuff, mostly about .5 inch thick). He reported doing pretty well making and selling about 4'x8' playhouses and forts.
I did not equip with Shopsmiths in spite of the setups but because of them.
1 1988 - Mark V 510 (bought new), 4 Poly vee 1 1/8th HP Mark V's, Mark VII, 1 Mark V Mini, 1 Frankensmith, 1 10-ER, 1 Mark V Push-me-Pull-me Drillpress, SS bandsaw, belt sander, jointer, jigsaw, shaper attach, mortising attach, TS-3650 Rigid tablesaw, RAS, 6" long bed jointer, Foley/Belsaw Planer/molder/ripsaw, 1" sander, oscillating spindle/belt sander, Scroll saw, Woodmizer sawmill