Do you have any ethnic/import groceries near you? I've found that a lot of the more "exotic" foods that are a little more pricey at a regular grocery store or health food store can be a lot cheaper at an ethnic grocery.
I've never tried dulse. Can I ask how you use it? What the taste is like? It's the fishy taste that I don't care for with seaweed (or does fish taste like seaweed...? deep thoughts!) and I know that different seaweeds have different levels of it.