What is the average cost for an internet tablet?

It depends on the device. Here are the most popular Android tablets with prices:

1. Asus Transformer Pad Infinity: about 500 dollars
2. Samsung Galaxy Note 10.1: 470 dollars
3. google Nexus 10: 399 for the 16GB version and $499 for the 32GB model
4. Asus Transformer Pad TF300 (16GB): 350 dollars