The important difference is not the price, but the extent of the corruption. A politician whose public persona is clean, law-abiding, respectful of norms and institutions, and generally benevolent will be limited in how far they will go to abuse their power and sell out their country -- even if they are secretly very cynical and amoral. A politician who is openly corrupt, above the law, norm breaking, and vindictive will be free to do much more damage.