I'd like to weigh in on this issue. There is "expensive" and there is "too expensive". Yes, compact hay equipment is expensive, compared to the out-of-pocket cost of raking it up and piling it by hand. But "too expensive"? Well, that all depends on the job you want to do and the tractor you want to do it with. You can't run a conventional square baler or round baler with a compact tractor, period. Yes, you might have the horsepower, but you will not have the weight to operate it safely. And you will not be taking a conventional square baler through a 6 foot gate. You will not be baling between tree rows in an orchard. You will not be baling areas along creeks and buildings that otherwise are maintenance headaches.
Another issue is hay quality. As about anyone will tell you, if your hay field is less than 10 acres, you will have a heck of a time getting anyone to come bale it for you. If they ever do show up, it will generally be way too late and the hay quality will be poor. People who buy compact hay equipment want to bale on their own so they have good quality hay to feed their animals.
The most important issue is tractor size. Let's face it, people love their compact tractors. They are easier to use, easier to store, and use less fuel. A lot of people don't want to own a 40+ horsepower tractor. Compact hay equipment brings haymaking to even subcompact tractor owners.
And just because a piece of equipment is smaller, that does not mean it is lower quality or is proportionally cheaper to produce. Think Mini Cooper versus Ford Econoline van. You don't choose between those two based on price, so why would you do that with hay equipment?
So is a mini round baler too expensive? Is a Harley too expensive? Is an Iphone too expensive? It all depends on your point of view I suppose.
