Poolish is frugal
I've recently made the Struan (struan? no cap?) bread from one of Peter Reinhart's books and it was wonderful! Tender and tasty. It probably helped that I used a mixture of heavy whipping cream (leftover) and water for the liquid.
There's just one drawback to the recipe: it calls 2 tablespoons of yeast. Yeast is expensive, even when I buy it in bulk from my food co-op. My usual bread is a ciabatta made with a poolish. I'm using 1/2 teaspoon of yeast total (1/4 for the polish, 1/4 when I mix the final dough). I can eke out a bag of yeast for months.
There's something to be said for poolish. Of course, sourdough would be even cheaper. I wouldn't have to buy any yeast at all. I've found, alas, that my baking gets erratic when I have a big freelance assignment. I resort to my frozen loaves and forget to feed my poor starter. Poor, doomed starter :(