L.M.
Do you already have a place to stay? Rather than staying at a place that is right on the beach, look for somewhere that is within walking distance to the beach, it may be a pain to carry all those items back and forth, but you can usually save quite a bit. Also, in most cases you can rent a house/apartment for less than staying in a hotel. Of course that means, you'll have to do some cleaning, and extra packing - it may not be your idea of vacation.
We do several long weekends during the year. Our way of saving is we only eat one meal out a day. A try to stay at a hotel that includes breakfast, or I pack fruits, yogurt, and cereal. I have a hot pot that boils water in 2 minutes, so we can make oatmeal, hot tea, hot chocolate.
Stock up on water bottles, or better yet buy a 2 gallon cooler and fill it each morning with ice and water (best to use bottled 1 gallon containers when staying in a beach area).
Stock up on the snacks too. Don't bring any money to the beach with you so you won't be tempted to just treat yourself to that $2 icecream bar.
Have a great vacation!!!