After installing ioncube an curl library on my host, i've bought and installed Parainvite.
I just find the component (and it's plugins and modules...) Amaizing and very useful for a websites that wants to increase his number of members.
Mike helped me very quickly when i needed his help and we don't find that everywhere.
80 euros is nothing regarding what the component will bring to my website.
You can have a look and test it by registering: