::EDIT:: Ok, just ignore this. Turns out I was just told incorrect info by a bunch of people, there IS a seed machine in the game already
A seed maker exists in the game, so you wouldn't need to modify anything else. I don't think it gives more seeds for higher quality crops, though. That'd be a nifty function.
This... actually IS in the game. http://stardewvalleywiki.com/Seed_Maker You get the recipe at Farming lvl 9, so I can understand why there's a bunch of people who don't know it's a thing, but it is.
I think CA was fair in making the seed hopper/maker come later in the game. Toward the end you start getting toward end-game stuff, and not having to pay for your seeds as much is one of them.
Well shit I haven't gotten that far, but I've had multiple people tell me there wasn't one in the game. I guess I'll pull my head in
Hahah, don't worry about it. Everyone mucks up once in awhile, try looking at the wiki for the game, it has a good grasp for anyone needing a easy-to-read walk-through for the most part.