You know...funny thing happened to me on the way to work.... uh... I was snooping around because we need a webinar solution in the near future too. And you know that things are always changing.
I found GVO Conference for less then $10 a month to get started. The nice thing I like about this solution is it seems there is NO DOWNLOAD which makes it easier for people attending to log on. (Hate when things get complicated with downloads and then things go wrong.)
I have NOT used this service; I am NOT an affiliate of this service. I am also not sure if I should be posting a link...but for the good of helping, here we go.
Good luck and I hope this helps!