scrimp and save

To spend as little money as possible; to be especially frugal, especially with the aim of saving up for something bigger. Ever since we had our second child, we've had to scrimp and save to make sure they both get what they want for Christmas.

skimp and save

To reduce or limit one's spending in order to save money. I'd love to go out to dinner with you, but I'm really skimping and saving right now. I'm sorry, honey, but your father and I can't afford to buy you a new bike right now—you'll have to work more hours and skimp and save.