I believe it's just a matter of understanding how the workshop works.  Some workshops are "by invitation only, " but that's unusual.  Some might have academic prerequisites.  Usually, they're just happy to get your money and fill up the class/workshop.  I would not consider any of these situations to be an offer by those conducting the workshop.

An offer would be if they "offered" you a scholarship/waived the fee.  But I can't imagine why they would, unless they were having a really hard time filling up the group.

If you really needed to take this type of workshop  -   in connection with your job, or for academic credit   -   you might be looking at several possibilities, and decide this is the best for your particular needs.  It also might be reasonably priced and be conducted by reputable instructors.  So you might say it's the best deal you're going to get.  But "offer" is definitely the wrong word.

  - A.