CamelCamel is FREE and no need to sign up or give email address. Just copy an url from AMAZON and paste it into CamelCamel and you will see all past prices including a very nice graph.
I just ordered mine from Amazon - it will arrive on April 11th, which seems like a lifetime to wait, LOL. I live in Minnesota, so will be looking for a group to associate with there....73s to everyone!
No. The 436 has a lot more memory; you can program it with every licensed radio system in North America. The database that comes with it does exactly that.