I'm a nanny, and the family I work for swear by the Brita filter they have.
You are smart to avoid using the cards as much as possible! I carry two; one is my 'pass' into Costco, but is otherwise not used, the other is for emergencies (Like when my car battery died in the middle of a busy day and AAA had to bring me a new one). I pay off the whole balance (if there is one)every month.
We Rarely eat out. When we do, it's usually for breakfast on Sundays (cheaper than dinner!) or for pizza, or ice cream.
You're not Scrooge. It's only smart in this economy to make your money go as far as you can.
Check out the grocery stores in your area. We have one that sells "mark down produce" and I scoop up great stuff! Half price red peppers because one in the bag has a spot to cut off! Half price celery because there are a few wilted leaves at the end. Another store has markdown groceries; a box of cereal half price because the corner of the box got 'dented'. A can of soup half price because the 'shelf date ' is approaching.Good luck!!