AT settup? Ttalk to Mike Hattrup
I see three categories of AT gear out there. There is the so-called "freeride" crowd that uses the beefiest gear available, maybe skinning just above lifts or huts and burling through stuff, the do-it-all crew that has pretty beefy gear but does a fair amount of touring, and the superlight touring/racing folks who have insanely light gear and dance over anything. The difference in weight between these categories can be enormous. The standard dynafit binding, for example, is over 3 pounds lighter than the fritschi freeride binding.
I'd start with something cheap, maybe used, until you put on a bunch of miles in backcountry snow. Otherwise you'll probably thrash your fancy new gear when you are wiping out in breakable crust, wind-hammered junk, rime, rocks, etc.
The advice to put most of your money in on boots is spot-on. I'd go new here myself, or get some older boots and buy some thermoform liners. Sierra Trading Post was selling dynafit thermofit liners for dirt cheap just recently. They are light.