Long time Tool fan. First time to a concert, and looking for advice.

I'm a long-time listener of Tool but I've never gotten a chance to see them live, so I'm very excited to see that they are touring. I haven't ever gone to a concert of this scale and I am wondering a few things. A couple of friends of mine do concerts all the time and seem to think $100 is outrageous for a concert but I don't have any reference for this. What are the tickets at face value? I'm want to buy some for the Atlanta show and the cheapest are $75 at the moment, can I expect them to go up til showtime or what?

And my second question, is it worth getting floor tickets? Or can I still expect a good experience from anywhere?
Also any other advice would be great. Thanks!

EDIT: Thank you to everyone for your responses, I just downloaded my tickets. I definitely got some great advice, I really appreciate it!