Four. At home, my original modified Oppo 83 quit playing Region B Blu-Rays, so it was retired in favor of the now-discontinued Sony UBP-X1100ES, also modified for Region B playback. An unmodified Oppo 83SE is in my office, primarily for stereo and multi-channel audio The only negatives on these old 83s: they don't support FLAC.
I acquired a second-hand 103 so I could rip SACDs and DVD-As to an external hard-drive. Unfortunately, I'm too old and stupid to figure out how to do that, so years later it still sits in a box. I fortunately acquired a 205 during Oppo's last call for orders. I immediately took it to a suburban Chicago shop for an all-region Blu-Ray modification, but it remains boxed up in my office. Why? It's for my old age when physical media players go the way of player pianos and 8-tracks. Okay, I'm 76 years old, so I've already reached that point. But digital media is targeted for eventual extinction. My 205 is ready for service, and there's no way I'll get sucked into buying new audiophile vinyl.
I suggest you unbox those two Oppos and use them- even just a little bit once in a while. It's not good for machines to sit idle for long periods.