Just like the guys in your gym, doses are going to be different for different people. The better genetics you have, the less gear you have to use. Also, as guys get older, they tend to get a little smarter and a little more concerned about longevity. For a lot of the guys that have been around for awhile, they aren't going to be making huge gains anymore. At best, 7 lbs in a year, of pure muscle, would be outstanding for a well developed pro. So if they are doing everything else right, training and diet, there is going to be a point of diminishing returns, where 1800mg test isn't going to make a huge differnce from 1000mg.
In the 212, guys are using far less than in the open. I can tell you that one top level 212 competitor, that you see in videos and magazines is running a total of 750mg of TOTAL HORMONE into a show. Thats test and other drugs combined. He is also using higher GH, 10iu. This is the far extreme of the genetically gifted. At the other end...well, it can be a dark and dangerous place. If you can imagine it, there is probably someone out there taking it.
I don't know about the older school guys. Priest has publically said that he took next to nothing. Maybe he did. I would believe it's possible. He was a very gifted athlete and may not have needed so much.
How does all of this translate to the real world, for bro's in the gym, trying to get big? Well, no one who is below the national level needs to be running tons of gear. If you can't get there without it, it isn't going to give you what you need. Someone who is going to turn pro won't need much at all, when they start out on the state level. There are a lot of guys out there, trying to push their genetics, taking everything under the sun, thinking it's what they need to do. So yes, in some cases, NPC guys are taking far more than pros