I used to have a little to do with market management. Most successful vendors, the ones back year after year, seem to subscribe to the adage: "pile it high, kiss it goodbye!"
I'll talk about one guy who I haven't seen in years who tried direct marketing of produce for a couple of years and, I'm sure by his own admission, failed. He might have other ideas on the reason but he would tell me something like, "if I can't make $400 on a Saturday, I shouldn't show up!"
Now, I would look at him and nod my head but all the while thinking, "what are you talking about?! You haven't brought more than $150 of product!"
You are doing the right thing trying to reason it out during the right season. Putting a pencil to the paper and doing some number work is the way to go. You cannot account for everything but don't think that you have to make X and then not have sufficient product to make it happen.
Doing a Google search for sweetcorn yield from site:edu will give you the Cooperative Extension's ideas on that crop or many others. Stagger your sowing to have some supply consistency. Satisfied customers are important and they aren't satisfied if they show up an hour after you get there and 15 minutes after you sell out. It may do your ego good to know that there is a demand but satisfied customers are loyal customers and they will be happy to see you show up, season after season. Consistent sales are what you are looking for.
Otherwise, talk to a produce company. Have them tell you what they will pay you, for how much, when, and how they decide for themselves on standards. Shoot, just turn it all over to them and a farm manager. Move to a nice home with an ocean view and forget about the logistics and hard work of it all. ... Sound like I have some biases? Heck, I've known "farmers" who can't even tell you what crop is growing on their land.
There is not likely to be any crop insurance for you, in any way, shape or form. Well, now that I think about it ... the payday loan guys might have something. Stay free of them.