I custom hayed back in 1994 -97. I ran 3 double bar Kosh mowers, a 30 foot and a 42 foot Rowse dump rake, plus a Case IH 8465 round baler. The first couple years weren't too bad. I could find help, and had good hay to put up. The last year I had little to no help, a lot of either swamp ground, or upland hill ground to hay, and still ended up with nearly 4200, 1300 pound bales for the year.
The first year I custom baled at all was in 1983, and I got $7/bale. Made 1500 pound bales. In 1997, I was getting $6/bale, and they wanted me to make 1800 pound bales. The cost sure never went down either.
If you have the equipment, and a neighbor like Soapweed, who pays his custom hayers well, and gives them the better hay ground, it will work. BUT if you go out and buy the equipment, travel long distances, and don't get the quality ground, NO it won't work.