What is the cheapest "jar" (i.e. not immersion) blender that will survive daily blending of hot liquids (100 degrees celsius / 212 degrees fahrenheit)?
Your standard Oster style blender will do fine. That particular blender has a great advantage in that replacement parts and "upgrade" parts are super easy to find. Oster I still use an Oster blender that belonged to my grandmother. Frequent blending of boiling hot liquids will wear out the o-ring, but o-rings are cheap and easy to replace. You can get a perfectly good old Oster at a thrift store for a song.
Read this too: How can I safely use a blender with hot liquids?
Here's good info too from About.com: "Blend hot liquids carefully, starting on lowest speed; leave lid cap off for steam to escape and fill the jar only half full, allowing more room for expansion. You may need to use a hot pad while holding down the lid during operation."
Knowing in advance that you want to blend hot liquids, you might want to choose a glass "heat shock proof" blender jar instead of plastic. Plastic should remain structurally sound, but it will get hazy.