It really actually depends how you go about it. It can be cheaper if you stay a little frugal with your money. The chicken fencing is a one time cost.
You can cut some of the cost for seed by planting extra vegetables for a seed crop the first year and then harvesting the seeds in the fall/winter.
Staying organic won’t cost more, it just will take more time. That’s why organic foods cost more, the labor cost is higher.
If you want organic fertilizer you can use manuer if you know where to get that or they sell organic fertilizer. Fertilizer can go a long ways.
Make sure your cold weather greenhouse is well insulated, this will save on electricity or propane. You could even buy a windmill to not only power your greenhouse but also collect on extra energy it generates from the electric company.
Buy some cold frames to save room from your green house, for those vegetable such as cabbage, that can stand a little cooler spring.
Preserve or profit from extra food, don’t let it go to waste, it’s only money you’re wasting.
Hope this helps you out.
It all depends on what you grow and how much you grow. It’s not always cheaper….but it always BETTER.