Franny wanted to go to Spain; however, she could not afford the exorbitant plane ticket.
The word that best fills in the blank is "however". In this sentence, "however" is a connector since it is joining two simple sentences: "Franny wanted to go to Spain" and "She could not afford the exorbitand plane ticket". Moreover, this connector is used to emphasize the contrast between the ideas presented in the two clauses. When "however" is added between two sentences, it is preceded by a semicolon and it is followed by a comma.
