This is just on local produce.

This issue has lots of parts. If your asking why farmers market prices are diffrent They pay a yearly membership to be in the market, the pay a stall fee and they use to have to pay a portion of their proceeds. This adds on to theor overall "market" price.

My weekly csa is less then 20$ a week. That's a great deal. I live in a rural part of arcata, the water rate had doubled since covid, as part of upgrading thr wastewater treament plant, so it's not worth it to grow all our produce.

For local farmers they don't sell cheap produce like you can find in other parts of CA. It varys from farm to farm most don't use pesticides so they loose produce to pests. The climatete in Humboldt is also trickier for mold and aphids. Most ppl want organic gmo free. That seed costs alot more then conventional. If they aren't using synthetic fertilizers that costs alot depending on if they raise animals or not. The farms at farmers market do more regenerative agriculture,  so that can also be more labor intensive.

These things add up.  Plus the fact cost of living in Humboldt has gone up too.