A lot of Monster cables are manufactured by companies that also build low-end cables. They do build to Monster's specs, which will often include using a thicker cable, sometimes better strain relief, and sometimes upgraded connectors.
However in many cases, especially on digital cables like HDMI and DVI, a lot of this is just building to overspecs. You can build a perfect cable for the application, say a 2 meter HDMI to HDMI cable for very little cost. You can make the cable thicker, the connectors heavier, etc., however it will not transmit digital data any more reliably than the cheaper cable. You can hook up an analyzer and the data error rates will be identical. The overspec cable & connectors may cost $3-$5 more to use, and they mark up the price 500% or more.
Again, this is assuming that you are buying a properly build HDMI or DVI cable. It can be done correctly for a very low cost (around $1-$2), but it can also be done incorrectly for a low or high cost.
http://reviews.cnet.com/4520-11246_7-6361815-1.html
http://searchwarp.com/swa34479.htm
Consider this cable from monoprice. It is built to overspec. It uses thick 24AWG wires, has large ferrite filters, gold-plated connectors, and a heavy duty cable jacket. It is $18.80. This is probably better built than the $100+ Monsters.
http://www.monoprice.com/products/p...cs_id=1023102&p_id=2219&seq=1&format=2&style=
Their standard HDMI cable, which should work just as well, uses 28AWG wires, smaller ferrite filters, gold-plated connectors, and a standard cable jacket, sells for $7.65
http://www.monoprice.com/products/p...cs_id=1023102&p_id=2412&seq=1&format=2&style=
And you know what? The $7.65 cable is still being built to overspecs. You don't need gold-plated connectors on a digital cable. And you won't always find ferrites on $50 cables. This is the cable that I compared to Monster and found no difference in performance.
So if you really want an overkill cable, that well exceeds HDMI specs, there is no need to spend any more than the $18.80 on the super duper monoprice cable.