I've setup a webpage to list all my TI99 cassettes, command modules, books and magazines I have for sale. I'm pushed for space and time to keep the collection these days so letting it all go to good homes! If you are interested in buying anything or to receive additional photos, please contact me with details of what you are interested in. I'm in UK so please note that shipping to places outside of UK can get expensive!
Webpage with everything listed is here: http://ti99.atspace.co.uk/
I've got a few more items to add including a load of TI99 hardware - I'll get those listed when they come out of storage.