Simple, cheap, and farmer's market accesible

I'm a recently unemployed student with ample access to farmers markets looking to expand my horizons, and not my budget. When I was employed, I dined out half the week and the other half cooked whatever I felt like it ignoring expenses. I generally shop TJs for most staples, but do have access to a limited south-east asian market for specialty goods, as well as tons of chain grocers.

Mainly, I'm now looking for cheap, relatively healthy, foods/recipes for what I can get cheap and fresher at the local farmers markets. High calorie is also somewhat appreciated, since I tend to be underweight.

My current staples, and literally all I get, is as such:
Potatoes(bake in quarters or boil and saute)
Kale(saute)
Green Beans(boil)
Spinach(throw into scrambled egg whites)

I would really like to get farther than just this, without breaking the bank now. I live in southern California.
What tips or simple recipes do you guys have for bang-for-your-buck farmers market veggies?
I'm very open to explore, except asparagus(eww), I just need to keep things simple and cheap.

Thanks a lot.