You need to contact the vendor. I think the ebay page is mis-quoting the 7" LCD monitor vs the 7" HD specifications. Note the native resolution and the brightness and compare each in the manuals. The manual says the native resolution for the 7" LCD HD is 800 x 400, which is the same as the Lilliput that many people use. Brightness is the same as the Lilliput.
I recently (January 2011) purchased an LCD4Video 7" monitor and it was a bad experience.
A few years ago I had purchased a 7" monitor from LCD4Video and it was great. They were using a name brand LCD screen at the time, and it was just what I needed. It's still going strong, and I recommended them to others.
In January I bought another, and my experience couldn't have been more different: Even though it had two composite inputs, it could not deal with two signals at the same time. The signal on AV2 would override AV1, until I unplugged AV2. The picture was also flickering in and out, at that. I got a new cable assembly, and then a whole new unit, but the same problem persisted.
I then noticed that when it was turned on with nothing connected, a message appeared on-screen, "NO SINGAL." Clearly they've switched to a cheap Chinese manufacturer with no concern for quality. They were good enough to refund my money. Perhaps they'll get their act together and start using quality parts again.