RJ,
I am a licensed RE Broker in Texas. In addition to all of the potentially rough legal waters you will be navigating with this strategy, there is also the issue of timing for your deals. Real Estate is a slow game until it's time to move. When that time comes, you will need to be able to move....and move FAST. Because of that reason alone, I would recommend gaining access to some kind of comparable engine on your own. You don't want to be sitting in a living room negotiating with a seller while watching 3 or 4 investors come through the home to look at it (while you're there, by the way) and make offers while you still have to leave and find a Realtor to run market data for you.
Sometimes you need that analysis in a matter of hours at the latest. A day is too late. If your Realtor is busy, or out of town, or whatever, you may have just lost a deal because you didn't have access to your own market data.