Here's a good read from the New York Times, featured on the Yahoo! Finance section about making cost-effective decisions when considering trade-offs in technology purchases.
Here's an excerpt:
PAY FOR TV SIZE, NOT REFRESH RATE As Matt Buchanan pointed out in a still-useful post on Gizmodo.com a year and a half ago, every television manufacturer has a sweet spot when it comes to price and size. Going to 50 inches from 42, Mr. Buchanan explains, may cost you $200, but going 54 inches from 50 could cost $400 more, so 50 inches is where you would get the most for your dollar. Every manufacturer has its own sweet spot, so it pays to look at the lineup and see where it is.