<<It would be great to have your own ISP, but one might ask why? :)>>
The point isn't necessarily to have your own ISP, but perhaps to have your own WWW, FTP, IRC site or something to that effect. I guess it all depends on what you want to do with the net. If you just want to USE it (as in surfing for info, etc.), it's not likely to be very important (although ISDN speeds would still be nice for browsing and downloading files). On the other hand, if you feel like you have info other people might want, or if you have something else new and appealing to offer and would like to CREATE something for the net, having your own IP address and server could definitely be worthwhile (in which case an ISDN line may or may not live up to your requirements).
