My square baler is at least as old as I am (50), it’s the only square baler we have ever had. It might sit in the barn for 2 seasons and not get used, but I can pull it out of the shed, grease it up, and go right to baling.I actually can't see the economic utility in keeping a baler around to do 300 small squares, unless it's in perfect running condition and serves as a backup to clean up a field if the round baler breaks.
But also... the economic argument for a lot of what we do on farms, especially small ones, is mostly out the window anyway.
My "magic number" to justify having a baler of either type is around 3,000 small squares, or about 150 round bales... either for sale or your own use. Otherwise, I would try to work with a neighbor that has the other type of baler... which isn't always possible either... farmers are staunchly independent people. To that end, I can think of a few instances, where farmers around me have more modern small square balers, in better condition than mine... and they haven't put a single bale of hay through them in a few years or more...as they have either switched to round bales, silage... or gotten out of hay completely, but aren't forced to sell anything.
I am working with a neighbor to put about 30 rolls here at my place. I’ve got all the equipment 10 miles away at the main family farm, but I worked out a deal with my neighbor so I don’t have to move all that equipment back and forth to my place. Basically I have a 20 acre field I wasn’t doing anything with, so my neighbor and I turned it into a hay field. We split all inputs, he has the equipment, I own the land, and we split the hay.