ok... apparently my point isn't getting across. Maybe it's just that the site isn't very good. When we were public members, we searched for caches (probably 10 times) in the area where we put them. These never showed up. When I was told there are two close to it, I was pissed. Now that we're premium members, I see the other caches.
How are public members supposed to know where NOT to place a cache if the premium ones aren't shown? I say... make it separate. 500' from each public cache, and 500' from each premium cache. Separate tiers. If you find the wrong cache, who cares. That's why you put the ID on the box and log.