Is it ok to buy the display model?

Here is my list of yay and nay for buying display models of technology:

At Full price:

• Nothing

At Discounted price:

• Printers
• Scanners
• Mobile phones
• Speakers and hi-fi units
• Desktop
  

Should avoid:

• Monitors and TVs
• Laptops (they suck up dust and get smashed a bit by unkind customers)

Fell free to add your own here by commenting!