how to economise on yeast

I find it difficult to get good quality yeast. I read somewhere that a piece of bread dough can be stored in the fridge and can u be used the next day or later on for mixing in the next bread as a yeast or starter(something called chef I think). Is this true? I don't want to use a sourdough starter but would like to ecomonise on yeast? I made a polish for my two bread attempts can I save some of the polish and use it the next day or within the next week. Any advise.
shi