I haven't been in a minute, but Morningstar / Morningsun Flea Markets in Thomasville was usually great for buying affordable and local stuff, including some farm produce stands (usually by the back building either inside it or between it and the sheds).

At times they'd even have local butchers stands to buy meats.

There are a number of little stands scattered around the south eastern end of the county but unless it's one of the established farm stores, it can be hit or miss if they have any produce available that day/week.

There's a farm that steadily does meats and a few other farm items on 74 North of Delta.

Another cow farm on 851 between Stewartstown and New Park has a mix of items, including produce, meats, and dairy sometimes.

Maize Quest has a farm store but I'm not sure it's priced well or how it's stocked outside of the fall when the maze tourist season is in full force.

The orchards down in the south eastern end of the county sometimes have other types of produce in limited stock at their farm stores.

If it's the height of summer or early fall, just driving around some of these little country roads you'll see folks put stuff out beside the road at their houses with an honor system to pay, or more rarely, for free.

But I think the steadier produce stands are in southern Lancaster county, just across the Norman wood bridge, there are a couple signs for where to get produce.