When is it "Worth It" to Save Money??

As a frugal bargain-hunting type, I take note of opportunities. Some, I'm too lazy to partake of; others--like coupons--make my head spin. Other opportunities--like the 30% off one book at Amazon that I posted on yesterday--take no time at all.

Today another Amazon deal passed across my purview: if you link your Twitter account with your American Express card and spend $75 at Amazon, you get a $25 statement credit. Go to American Express's facebook page to see for yourself.

It just so happens we want to buy something that costs $80 on Amazon (see below--another exciting holiday purchase). We don't have a twitter account. We do have an American Express card. Should we do it?

As often with these quandaries, I emailed Frugal Son and asked him. Now I'm asking you.  (Hmmmm. The item we want has gone down in price, perhaps for Cyber Monday??)