I have a Scientific Atlanta 3250HD box for my new Panasonic 42PX77U display. I will be running the cable signal through an HD Tivo player that has an HDMI output. Since the cable box will be connected to the tivo using the coaxial cable will the signal from the tivo box through the HDMI cable be as crisp as if I was running the signal directly from the cable box to the TV using DVI?

I think the answer is yes, but you never know.

Also, here is an HDMI cable question. Do the $100 HDMI cables transmit the signal quicker than the $40 cables or is there more to it than that? Why such a huge swing in price from one set to the other?

You can't output HD from the 3250HD and record it on the HD Tivo, the analog RF output on the 3250HD only sends out a 480i signal. You need to rent a cablecard for the HD Tivo if you want to be able to view and record premium HD channels.

As for the HDMI cables, digital data is digital data, as long as it gets from point A to point B, the PQ will always be the same. I wouldn't pay $40 for a cable, that's still high, check out forum sponsor monoprice.com