I found the answer to this question interesting in that he referred to a "75 cent word". I would have called it a 50-cent word, not because I undervalued his answer but because that is how I have heard the phrase. I thought at first that am old enough that inflation caused the difference, but I found a 1976 reference to 75-cent word from 1976, the earliest reference to the phrase I found in a quick ngrams search.
What is the "right" value to use in the phrase "?-cent word" (or, what was the original)? Has it changed over time? Do non-American English speakers have alternative expressions in local currency?