Right smart spells is a colloquial expression commonly used in the Southern United States to denote a significant quantity or degree of something. However, it may be unfamiliar to those outside of the region or non-native speakers of English. There are a variety of synonyms that could be used instead, such as "a hefty amount," "a considerable sum," "a substantial quantity," or "a considerable degree." Other regional expressions that might be used in place of right smart spells include "a big ol' bunch" or "a whole mess of." Ultimately, the most appropriate synonym will depend on the specific context and intended tone of the speaker or writer.