Response time(typical)

Obviously a low response time should be better.

You probably won't notice any difference unless playing a fast video game.

A high resolution such as 2560x1600 ought to demand more from the hardware in order to get a low response time.

To get low response time, they may have to make compromises on other characteristics, such as viewing angle or color accuracy.

My 30" display should be used for a large desktop area. What happens if one plays a DVD on this display?

You have a choice of viewing sizes. If you are close to the screen, you can play it in a window at the full DVD resolution of 720 x 480, and have lots of other windows on the screen, or you can enlarge the window, or go to full screen mode. The DVD player software will enlarge the picture as needed.

Does DVD player change resolution and response time

No.

or is this independent of resolution?

You can change the display resolution, but LCDs look best at their full resolution, The response time is fixed by the design of the display.

Or should one avoid watching movies on this display? That is: What is the primary penalty of a high response time?

Movies are shot at 24 or 25 frames per second (about 40 ms), so will look file on a 16 ms response display.

Does improved response time have a big impact on price?

No, but other display characteristics may suffer to get the fast response.

If I understood correct then display refresh rate don't apply to this type of display.

LCDs usually can only run at 60 Hz refresh rate. Unlike a CRT, there is no fading of the image between refreshes, so 60 Hz doesn't cause flicker.