Long time bump, but here are my thoughts. First off, do it if you can. The Open is about the courses and how they make it Open ready. I've been to Shinnecock, Pebble, Pinehurst and this year at Oakmont. All of them were special experiences for the golf fan although my favorites were Shinnecock and Oakmont. Television doesn't show the course adequately.
To your question, the USGA sells the tickets on their website and it's usually not a problem to get them until possibly a few months before the tournament. The bigger issue is a place to stay. With vrbo and Airbnb it is somewhat easier. All of the accommodations are prepared for the event so it's usually pricey. If you want to go, I would recommend to secure your accommodations sooner rather than later. Also, the USGA does a great job with logistics in getting you in to the course. The bus system at all of the ones I've been to have been top notch.
Good luck and if you have any questions, ask away!