Any Online Resource For Checking DVD Prints?

I bought the Monty Python’s Flying Circus complete series box set for $33.99 on Amazon in 2011 which seemed like a good price at the time. Now it’s out-of-print and selling used for over $100. Is there any online film industry news resource for knowing in advance which DVDs are going out-of-print, and also which DVDs will be available in the near future? I hate buying something newly out-of-print at somewhat of a premium not knowing if the price will continue to appreciate or if there will be another print run in the near future.