Cerberus;325935 wrote The amount of sports in Summer is much greater, but so many of them need very little in the way of structures to be built, where as the Winter games need massive bobsled tracks and skiing courses. Summer needs a big pool, a big piece of grass, a long road (or at least several smaller roads that can be linked together in a course to become one long one), a lake and a river.
Yeah building those mountains can get pretty spendy.
There are way more events in the summer games. Every venue would need stands for the fans, security, and transportation for the athletes. You would also need a huge athlete village. In addition to Milo's list, there is also synchro, waterpolo, team handball, weightlifting, martial arts/wrestling, equestrian, field hockey, soccer, table tennis, badminton, kayak, gymnastics, boxing and fencing which all need venues.
There were 198 events in the 76 Montreal Olympics, 86 in Vancouver 2010 and 312 in London.