Sunflower seeds are very common and you can buy them raw, roasted, roasted and salted, as bird seed, in chicken feed....
There are other ways to use sunflowers, though and to eat them. The buds taste similar to artichokes (which they are related to), and although they are smaller, they are a definite treat. I really like them.
Sunflower leaves don't taste very good to me and they seem to have a bad texture. But everyone's tastes are different, so that might be worth experimenting with.
Sunflower petals can be used to make jelly, tea or an infused oil that can be used for various things. (This is where a search engine comes in handy.) I have read that sunflower petal tea is said to take care of sore throats but no one has said whether they have tried it. I gathered some this afternoon to try.
Then there is sunflower oil, made from pressing the seeds. Certain sunflowers make more oil than others, so the development of black sunflower seeds has meant a better market product. Oil can be made from any sunflower seed if you can press it enough. I tried this one time and didn't get much oil, but I got some. If it was really needed, I could do it.
Sunflower sprouts have a wonderful flavor and are a solid food, not like some sprouts that seem to be there for the looks. Make sunflower sprouts in dirt or a medium and you can use the result as a side dish. This is one of my favorites in the winter.
Right now is a good time to start looking for them to harvest. Petals are beginning to fade here, but there is plenty of time for seeds (if one can beat the birds and squirrels). There are still buds forming, too and of course the leaves are still there.
Frugal? Well, yes. It's free food or drink or treat or even medicine, however you treat it. If it can replace something you would have to buy otherwise, that's pretty frugal, isn't it?