Posted by hkkm (602 days ago)
As Oski said, there is a range of accommodation both in Yosemite Valley and just outside the park. Current (spring) rates for tent cabins start at $39/night for unheated, ranging up to a cabin with its own bathroom for $126/night. I don't know what summer rates are, but probably more.
In terms of when to go, summer has the most pleasant weather, and all the roads are open, but there are a million people and you may not be able to get accommodation even if you book now. I've been in early summer (end of June) and it was really nice, lots of wildflowers and the road over the high pass was open, but some years it doesn't open until mid-July. September (after school goes back) would also probably be nice, but starting to get cool. Winter is beautiful, but you are limited to Yosemite Valley as they don't keep the other roads open in winter.
(I am based in Hong Kong)