I'm saving for a yurt life as well and I have a couple suggestions based on my own plans. First of all, if you don't have all the money together plan on doing things in pieces. So first you save up and buy the land, then get whatever utilities you're going to need in order (well dug, electricity run, etc.) then save up to get the
and yurt in place with its required
and heat source, etc. I would worry about getting the loft up and indoor partitioning done last as that could be rather cosmetic.
Also, I would look into the possibility of doing what you want with multiple yurts. The sort of thing that you buy one medium sized yurt to start and you cram everyone inside and it sucks, but since you're no longer paying thousands in rent you quickly save up enough that you're able to buy a smaller yurt to shove the kids in, then another for your own bedroom, etc.
something like that may be a pain in a cold climate, but it could be far more cost effective in the long term.
I saw one yurt set up that I liked where the family built a central cabin like space that housed the kitchen/bathroom/utility room with two yurts attached for bedrooms. I thought it was rather clever since you could build the expensive plumbed cabin bit and live in that for awhile then expand to more living space as needed. I just wish I could find that website again!
EDIT: Also, you might want to look at the Yurt Foundation. They have plans there for something called the Family Yurt that is supposed to be designed so that it can be built in pieces. They're solid sided yurts so they're not particularly mobile, but you could probably use the plans to get a mortgage since it more closely resembles a traditional house.
http://www.yurtinfo.org/the-yurt-foundation