With a thrifty eye refers to being conscious and careful with one's spending, and there are several synonyms that can convey a similar meaning. One option is to use "frugally," which means to be economical or sparing with resources. Another synonym is "parsimoniously," which suggests being excessively frugal or miserly. "Economically" is also an appropriate word choice, as it highlights the notion of managing finances wisely. Additional alternatives include "prudently," which means being cautious with money, and "conscientiously," which implies a diligent and thoughtful approach to spending. Ultimately, choosing the right synonym depends on the context of the writing and the intended tone.