You'll burn through more money in labor by opening up the device without damaging it further and yanking the proper chips than what you'll get for it in parts.
What people should do with old tablets and smartphones is smash them. I'm sure there are techniques to wipe a tablet, but do you really want to take that kind of risk with your personal data? Even one credit card number accidentally cached by a sloppily programmed app can cause you way more harm than the $25 you might get for parts. You may not be liable for fradulent charges, but you are liable for the hours on the phone, filling out paperwork, and the other hassles coming from having your credit card stolen.
When I dispose of hard drives, I smash the platters to bits. Doesn't take much longer than 1-2 minutes. I have yet to dispose of an Android device, but the same concepts would apply.