We went on the London Eye in May this year. We stayed at Crystal Palace site. Was really nice and the bus stop to London was just outside. It cost us £5 each per day to travel into London and the ticket included buses, tube and overland trains. We enjoyed 3 days in London doing this. Really recommneded, which is more than I can say for the London Eye which we personally felt was overpriced, too busy - the queues were horrendous even though we pre-booked our tickets. Not worth the money for us, but obviously that is only our opinion.