I used to buy the 2nd AC, 60 day pass. You need to purchase it with foreign currency and show your passport saying you are a foreigner/NRI.
As soon as I buy, I also used to plan out my trip and make the reservations accordingly.
All reservations are free and you can get into any train you want.
And..if you are traveling a lot, it is way cheaper.
My journey's started from HYD and HYD-DEL itself in AC 2 Tier used to cost 7-9k. So, $200 (USD) for 60 days was worth it.