Heck, why you're publicly discussing this...what's wrong with talking privately with Baron (not the moderator Magna) directly considering this is his forum and he sets the rates. I'm under the impression Magna is just the top dog moderator but doesn't make any financial decisions about the forum.
Simply, this is something you should have done right out of the gate (private discussion with Baron) considering its a business proposition and knowing this is a sponsorship forum. In other words, you don't want to be stepping on the toes of other sponsors that's paying Baron for the privilege to do what you had been doing freely.
Every sponsor forum I know, they all are like this...they want folks to pay to advertise, market or recruit instead of debating (negotiate) about such after the fact and publicly.
P.S. I'm curious if Magna gave you Baron's contact info involving you becoming a sponsor of ET after deletion of your recruiting (advertising) message post.