If all of your links are in html (not css/js/etc), then you could do this with a sed (on *nix), or with a scripting library (e.g. BeautifulSoup in python). If not, that is a complicated (potentially virtually impossible) operation, depending on how links are constructed, which I'm sure is why that product can charge what it does.
Example sed:
find directory -type f -print0 | xargs -0 sed -i -re 's:href="someoldpath/:href="somenewpath/:g'
But that's a pretty dangerous way to do it if things are not very nicely/simply laid out. Then again, if the old directory is a truly unique name, you could just find/replace that (again, unlikely).