I would also wait to buy an otoscope. I waited until my 3rd year to own one. I figured I would wait until I had had multiple practicum experiences with otoscopy before trying to perform it unsupervised. Now that I've seen a whole kit and kaboodle of ear craziness, I feel better performing it and making a more accurate judgment of what I'm visualizing.
I would suggest that once you're in an Audiology program as a 3rd year students, you can apply for a free otoscope through the Audiology Foundation of America (AFA). They typically have you read some articles and submit some type of quiz. It typically occurs each January. Beware, though, supplies run out quickly.
If you're really itching to own one, I would go through Oaktree's otoscope guide to help learn about the different types. As cidanu said, it's rare to have to use one at home, so I just own a pocket otoscope - nothing fancy. The clinic will provide that. But I still suggest waiting until you're a few years into your Au.D. program. Good luck!
I think it is a great idea to get an otoscope as early as you can. Practice on your friends and family. Get a feel for how the scopes work and get some experience on people that don't care if you accidently poke their conchas or not. Don't worry about getting the most expensive Welch Allyn scopes either. I got a cheap one from Dr. Mom. I used the heck out of that thing (someone stole it a few months ago..grrr). I've sent people to their Docs that wouldn't have otherwise gone had I not looked in their ears. After the proper training and enough clinical SUPEVISED experience, I even had an ear cleaning day for family and friends. All this talk about 'wait until your 3rd year' is obsurd. It's otoscopy, not surgery. Don't go scoping random strangers of course, but your close friends and family are inexistence to be your guinea pigs! You don't NEED an otoscope, that's true, but having one for your personal use is something I found to be quite helpful.
Another thing I found to be helpful is learning to use the otoscope with both hands. Being that it's a new skill set, your hands shouldn't prefer one way or another when you first start. So before you tell your brain to only use your dominant hand, use one hand for one ear and the other hand for the other ear. For instance, when looking into a left ear, I use my left hand to hold the scope and my right hand to pull the ear back. Opposite goes for the right ear. It keeps you from doing the 'cross-over' to pull on the ear.
all in all though: practice practice practice practice....whenever you can!