I think most of the guys on OC at least, have their sleds equipped to their liking and want to ride them when they go north. It doesn't make sense to own an expensive sled with associated costs and leave it sitting at home.
In a lot of cases there are there are 2-4 people going north together and sharing the costs of fuel and rooms so its likely still much cheaper than flying and renting. In our groups case, the trip up and home gives us a chance to enjoy the conversations and being with friends.