If we put in all the work and all the expense and take all the risk and the landowner just wants to collect a check it's worth about $15-20/acre. Most people with 5or 6 acres will tell you not to worry about the $100. It's not ditch hay. It's mainly grass hay with some legumes. Now it's not alfalfa but good beef cattle hay.
If your getting $300 for renting out row crop ground don't even bother with hay. It can't touch row crops if all you want is the money.
You're getting at the bottom line -- what is it worth to the hayer? Some portion of that is the most the landowner can expect to receive. That number is going to depend on a few other numbers, which vary tremendously by region. The first is the innate productivity of the land. The second is what it costs to take hay from it, including all inputs. The third is the market value of the hay.
Costs and market value are determined by local market conditions. To answer the question for yourself, you have to do some research about the local market. Answers from the rest of the country may be interesting but they're really not of use to you.
Just for curiosity's sake, I'll tell you about how things are in Rhode Island. I have nine acres of hayfields. Grass grows like crazy here, it's the dominant weed. My land used to be a sod farm, it's well watered and rich soil. I have someone come in and cut it once a year and that's all I do. No seeding, no irrigation, no fertilizer.
Last year the guy who cut it got 56 800-lb bales. That's 22.4 tons, or 2.5 tons per acre. He sells those bales on Craigslist for $40 each. That's $100/ton, or $250 acre, or $2240 for the whole cutting. I don't know what it costs him to cut it, but what I have observed is:
1. It takes a not insignificant amount of time. It's a minimum of four trips around the field to cut, tedder, rake and bale, more if it rains. Each trip is about four hours. Plus the time to truck all the equipment in and out, and gather the bales and truck them out.
2. It takes a not insignificant amount of equipment. In the course of the cutting I'll see:
* A disc mower
* A tedder
* A rake
* A baler
* A tractor to pull the mower
* Another tractor to pull the rake and tedder
* Another tractor to pull the baler
* A loader/backhoe to gather the bales
* A flatbed truck to haul the equipment and the bales
3. I've had several different guys do it, and they all seem pretty indifferent about whether they do it or not. Some years I haven't been able to find anyone to do it. Any suggestion on my part that I get anything out of it quickly ends the conversation.
If I had to guess, I would say that all told he nets about $1000 per cutting and puts in 40 hours beginning to end. That works out to $25/hour, which is less than I pay the guy who cuts my grass.
