Spurs earned £690m worth of income last year, according to data from the Uefa European club finance and investment landscape report, putting them ninth overall in Europe. That income would take a serious hit if they were to drop into the Championship. According to BBC Sport analysis, the reduction could be as much as £261m overall. One key area in which they would be harmed is ticket revenue, which earned the club £130m, the fifth-highest across the continent. Currently, Spurs charge an average of £76 per fan for each home match, with only five clubs in Europe costing more. Since building their new stadium for around £1bn, Spurs have focused heavily on selling hospitality tickets and corporate packages for matches in order to maximise matchday takings.…