Cost vs. Quality

Is it better to buy things that are expensive with the idea that said item will last longer and therefore be worth the money? Or is it better to spend less and if the item then breaks, at least it didn't cost that much to begin with?

My current dilemma: I am going away in two days. I do not have a sufficient piece of luggage. I want a bag that I can carry on, that will fit what I need for the long weekend and still go nicely into the overhead compartment. I am done cramming my heavy, overstuffed bag up there and I don't want to wait to check any baggage. I never got the expensive luggage that sometimes comes with getting married. We have mismatched bags of varying sizes, most of which are splitting at the seams. Though I just need the one piece for this trip, I went into the Kmart next to where I work and saw that they are selling 3 piece sets with a bonus garment bag for $69.99!!! If I want to really splurge, I can get the 5 piece set (also with the bonus bag) for $99.99! They nest within each other so it makes for easy storage in an apartment that only has two closets. They are not hideous... I have my choice of red, black or green.

It seems smart to buy the cheap nesting luggage, than to spend more than that on one name brand piece of higher quality. The way I see it, the bag can get beaten up, lost, spilled on, etc. and I won't be upset. Now if it were a $1000 Coach leather bag, I would be pretty upset. But then again, I am an adult and really should invest in nicer things. In all honesty, though, I'd rather spend the money I save on umbrella drinks and a massage. Problem solved.