The way I would describe my daughter's ex-boyfriend; "You can't polish a terd."
Your recipe is only as good as the ingredients you start with, "You can't make chicken salad out of chicken sh_t."
Caviar dreams on a hot dog budget.
Six one way, half a dozen the next.
If wishes were fishes, we'd all have full dishes.
To let someone know that you can't always get what you want, you might say, "People in hell want ice water."
Don't act pretentious, "Don't get above your raising."
My Pawpaw used to tell me that he was "going to go make me a big nickel," when he would go to work.