Buying a net at St. Andrews on Saturday and catching them yourself is an expensive proposition. In addition to that, weekends there are crowded with seiners, you would have to compete with many other nets for the available shrimp and the size will vary from small to a few jumbo shrimp this time of year. Should you decide to go the seine route, do your shrimping during the weekdays. While the initial investment is somewhat expensive ($190-$260, depending on length and height), a net will pay for itself after a few trips, if you have the time and don't mind the effort to catch your own shrimp and you could do it year after year. Should you decide to purchase a net, the best time to shrimp would be after the third week in August through the end of the season. The average size is much better and the number of shrimp you will catch are considerably better.
City Market and Poteets sell individually flash frozen shrimp for $50/5 lb bag. You could pick up 25 lbs for the same price as the bigger nets.
Catching a shrimp boat coming in is the better option if you have a boat and can actually get one to stop and sell you shrimp on the water. You would have to catch them as they enter the inlet on the way to the market. Occasionally they will anchor out at night in the inlets, if you can catch one there, you might be able to make arrangements for the next days catch and exchange phone numbers with the captain. Have never done this myself, but I would imagine others have.
Good luck whichever way you decide to go.
City Market is selling fresh shrimp, not frozen. Under $6.00 per pound (med) headed. They are right off the boat. Prices quoted must be when it's not scrimp season?
I regularly buy these shrimp 4$/lb with the head on. I buy directly from the shrimp boat captain. Right now is the end of the big white roe shrimp season. It'll be around the end of august when it picks up again.