depends. if you're already ranking on page 1 of the search results for Blue Fun Widgets, I wouldn't mess with it. If you change your title tag you're likely to experience a temporary drop in ranking for that page as Google readjusts where they think your page belongs. it would likely bounce back after a couple weeks, but you never know.

if not, i would suggest adding in 'Blue Fun Widgets at Great Sale Prices'... the second version is explains more about the page and would likely lead to a higher click through rate. It would also help target additional long tail phrases like blue fun widgets prices or blue fun widgets sale.

hope that helps.

It depends on what term you are trying to rank for and how much traffic you see from each term.

The 2nd term does sound more detailed but does not seem likely to be a term people would search for. That said your main keyword phrase would still be in there, it would just have a lesser keyword density.

McBrett is correct. If your site is already ranking well you might see a temporary drop (or improvement). It really depends on a number of factors. For example, if you have a ton of good backlinks to your site then there would likely be no change at all. Remember the title is important, but is only one of hundreds of factors Google uses.