Robin Good: YouDazzle is a web-based collaboration and conferencing platform providing file-sharing, Dropbox integration, VoIP and screen-sharing for up to 250 participants for $39/month (Pro version).
YouDazzle Pro also integrates, sharing and showcasing of presentations and any other type of file as well as video conferencing, webinar recording and support for mobile devices.
There is also a Starter Plan ($19/mo), a Free Plan as well as a 14-day trial.
Comparison chart: http://i.imgur.com/xEIOk.jpg
More info: https://www.youdazzle.com/product
Try it out: https://www.youdazzle.com/home