A parsimonious person is unwilling to spend a lot of money. You know those people who count up every penny when it's time to split a restaurant bill? You can call them parsimonious. Or cheap.
Stingy is the most common and general synonym, but there are many other near synonyms: thrifty, frugal, penurious, niggardly, penny-pinching, miserly, tight-fisted, tight. The adjective parsimonious was formed in English from the noun parsimony "the quality of being careful in spending" (from Latin parcimonia, from parcere "to spare") plus the suffix –ous "having the quality of."