I haven't tried this but maybe you could experiment since you're sounding adventurous.
If you open the sub.dbf using Excel located in the Aloha\data directory, you will find all your sub menus listed in columns and prices in rows.
I guess you could edit prices there, save, and copy back to data. Actually, copy the sub.dbf file to Newdata then refresh, this will automatically copy to data and restart all the terms.
I've never done this and I don't know if it will work. Of course backup data and newdata first. Do this before any live business in case of screw up.