Contact Dvduval http://forums.digitalpoint.com/member.php?u=6250 I think he can only tell you (or directory network owners malcolm, aaron etc. )
I have purchased 16 phpld licensed versions recently and david will answer you better about the discount. He does offer a bit though and I don't wanna say how much.
eSyndicat has unlimited license. Currently $149.00 But both scripts are different. (2.2 verion is expected of eSyndicat) not sure when it is coming out. so, check their web site as well.
Actually I already have 5... to its 21 in total. Stay tuned lot of things are gonna come up next year, I am considering 3-4 months for development.