It will hopefully be free of charge as long as usage is within reason. The server currently has php and perl installed on it, so those may be an option. Asp may be a bit of a pain to get working on a Linux server, and others will probably not be installed unless there is high demand and good reason why current systems don't work (any actions taken on the backend of the server itself are limited as there is only one person authorized to deal with that).
I would guess it will be a while before dynamic content is allowed though. It is much easier to setup just a place to dump files that can be pulled off (and yeah, having an independent webpage kind of requires that files can be downloaded directly). Any of the dynamic code systems are a security problem if not setup right, as they include functions for file and databases access. Assuming the server is setup securely for a normal server right now, people won't be able to damage other databases and can't access any files outside of the area used for hosting files. But it would still let them access other files that they shouldn't be touching (such as other users’ stuff or the main website) unless a fair amount of effort goes into setting up all of the routines needed to keep people in their place and to be automated when new members join. It would be one thing to have to just watch member sites for improper/illegal usage of their space, it would be a whole different deal if we had to worry about people accessing the wrong things (especially since even the admins can't access most of that stuff in case it needed to be fixed).