I had owned that same HP Compaq TC1100 for several years. I consider the $267 price to be at the top-end of what to pay for this machine. It's not a bad computer, but computer prices have dropped quite a bit since it's initial release.
If I were buying an older tablet, I would try to keep it under $200. If ebay prices have suddenly jumped, just wait a while and they will fall back to where they should be.