Why the massive price difference between 19" and 20" widescreen monitors?

[Vegeta]

Just looking at some monitor prices, 19" widescreen monitors seem to be going for nothing whereas 20" widescreen monitors seem to go for a lot more, for 1" difference, is there a reason for this?

 

[Kreeeee]

Because of the large resolution difference iirc.

 

[FrankJH]

as above - 19" 4:3 res is 1280*1024, 19" w/s is 1440*900 and 20" w/s is 1680*1050 so there is a vast difference in the resolution and cost of the panels