There are several things in this thread that I would like to comment on.
The first is the idea that upper level group lessons are not a good deal. I take this a little personally as my primary job in SS is teaching these lessons. It costs about $150/day to ski in a level 7-9 lesson with me. This lesson lasts for 6 hours. That's $25/hr to ski with someone who has intimate knowledge of the mountains terrain and conditions and is very skilled with matching students with this terrain. We do a good job of sorting students by skill, expectations, and conditioning. The average group size is around four. As far as I'm concerned that day belongs to the group and I am there it facilitate it for them. We can ski powder and cut lift lines, we can do skills and drills, or anything in between. I think all of the instructors who I work with in these lessons with are very good and the product is well worth the money.
In spite of what Phil says, it has not been that easy to get a job in my SS. Typically the hiring rate is 2-3 for every 5 that take the hiring clinic. I am generally impressed by the quality and potential of most of the rookies that I encounter each season. I'm also glad that I don't have to go through the hiring clinic again. I thought that I was pretty good my first year and I wasn't bad, but I am WAY better as an instructor now and get better every year. IMO there is no substitute for full time experience.
The original question had to do with the comparative value of camps vs. group lessons and other options. It would cost about $600 to ski in an upper level group lesson for four days. These days would run from 10:00-4:00. With line up and group sorting we start skiing for real around 10:30. Camps go up the early Tram each day and start skiing from the top as soon as the mountain opens. This is effectively an extra 90 min each day of prime time skiing. The early Tram privilege is usually only extended to private lesson guests at a premium price. In general the Steep camps are taught by the same group of people that I work with teaching upper level group lessons. In fact there was a move a few years ago to make the group lessons feel more like steep camp and offer incentives for groups to stay together for several days with the same instructor. In my mind the early starts, the back country day, video sessions, social events, and swag are worth the extra cost of the camp vs private lessons if you can afford it. IMO the group lessons are a great deal, even though the camp may offer more.
The idea that the S&D camp is only about tactics and that tactics are a bad thing. I have taught a lot of L8 lessons and I find that most L8 skiers have put a lot of time and effort into their skiing. For a lot of the skiers who I work with, a tactical focus can help them get more out of the technique they already have. A little tactical focus goes a long way in opening up tight steep lines and pegging the fun meter for most L7 & 8 skiers. Fun is Good! This is not to say that there is no technical focus, merely to state that tactics and technique are connected and can't truly be separated. Many people have only ever had the technical focus in instructional settings and are ready for something else to round out their big mountain skills. When I teach a technical skill, I always drill it into my students through tactical application in as much terrain as we have time for. I like Weems sport diamond model where the focus of a skiing student moves through 4 polarities at different stages of their development to keep the learning fresh and moving forward.
The idea that you can learn by following people who are better than you. There is no doubt that you get better when you ski with people who are better than you. The problem with this, as Josh tried to point out, is that if there is too large of a gap in the abilities between the weaker and stronger skier, the weaker skier can develop defensive habits trying to "keep up" which will hold them back from becoming a truly top level skier. I know plenty of people who ski fast and strong, but aren't very "good" because they followed people who were too fast too early in their development. This is mostly a problem when your "friends" won't slow down and insist on only skiing the gnar even when skiing with advancing intermediates. That being said, there is a lot of truth in the saying "if you want to be the best, you have to surround yourself with the best.
The idea that you can use a job as a ski instructor to improve your own skiing. This was true in my case. I had to relearn how to ski starting with the wedge . A few years of low level lessons and the demos that go with them really cleaned up my skiing. It turned out that I really loved teaching skiing and will probably do it full time for as long as I am able. I tell everyone that teaching skiing is a job. If you don't like the job, and not everyone does, it's going to suck for you. When you are teaching you should be focused on the student. Any learning you do is incidental. It's going to be hard for you if you need to be skiing black diamonds and you are on the bunny slope everyday. It's going to be even harder if you have the attitude that your clients are tourons or gapers. Some people would be better off participating in a race program or season long lesson program for locals than trying to teach.