Making a Jesus-Profit?

I receive brochures and ads all the time from organizations claiming to have the key to increasing our church's witness, increasing our church's membership, and increasing our church's giving. These are supposed tried and proven methods that have a high percentage of success. I can get all of this secret treasure for such-and-such an amount. Somewhere in these ads I am given the guilt-trip that it may seem costly, but the results are worth it. Some even have the audacity to say that if I feel that buying their secrets isn't affordable, then I'm short on faith. (This is my paraphrase, but that is pretty much what it sounds like). In addition, I am constantly bombarded with ads for sermons by other popular pastors (for a fee of course). I will admit that I have bought and read and listened to sermons by other pastors. No, I don't copy them and regurgitate them from the pulpit on Sunday, but during my sermon prep. for the week, I do glean what others have said on the particular passage(s) I am preaching from. A friend and mentor of mine calls it "eating the chicken and spitting out the bones." Years ago when I was a Youth Minister and filled the pulpit at church one Sunday, I pretty much preached almost word-for-word someone else's sermon (with his permission) and it was such a disaster, that I resolved never to do it again.
In case you aren't able to pick up on my tone in the previous paragraph, I'm having a problem with this. Maybe I'm jealous because I don't have a ministry product that can sell and e-mails aren't filling up my inbox from fellow pastors asking me to send my famous sermon transcripts that they've been hearing about. And I don't have a problem with sharing ministry ideas or sermon ideas. I think we should. When sharing these ideas, I don't have a problem with people charging to cover the cost of materials or administrative costs (I hope that is what is taking place with all these ads I receive). But it does bother me when someone seeks to gain a profit this way.
If someone is doing this for profit, this is what they are doing; they are holding back the growth of God's kingdom for their selfishness. I believe Jesus said something about the kingdom of God being like a treasure in a field. Once a man finds that treasure, he sells everything so that he can go buy that field. Jesus is speaking more of salvation in this case, but there is application to this topic too. Hypothetically speaking, suppose Pastor Bob serves at a church and follows God's vision to lead that church to be very effective in a certain ministry. People come to Christ in droves because of this ministry and the church thrives. Pastor Bob writes about what his church did and develops a generic method that other churches can adapt to their own contexts, which can also reach people for Christ they haven't been able to reach previously. What a tragedy if Pastor Bob decides he wants to make a profit on this and won't give his secret to the treasure in a field unless he gets paid for directions! If what he knows can really advance God's kingdom, then why not share it with as many as possible? Those are some potential serious eternal consequences just to make a few bucks!
Am I missing something here?