I LOVED the TI calc forums. I got my hands on enough parts (and went to radio shack to get the rest) to make my own cable from the parallel port to the 2.5mm jack they had back then.

I'm still amazed they cost as much now, as they did 30 years ago, but if you just realize you're buying a license for decent computer algebra system (CAS), at least in the ti-85/89/etc models, it kinda makes sense.