Tasta of wine and quality of a component set are two different things. I know you weren't directly comparing them
I'm with Madmods. A $60 component kit will sound way crappier than a $150 kit, and likewise for a $200, $300, and hell, even a $1000 Hybrid Audio or $1500 DLS 3 way kit. It's all in what you really want to do in the long run. If you think, even for a millisecond that you're gonna want to upgrade to an aftermarket 4 channel amp (I'd recommend it with our convertables), then you'll want to get a good quality speaker that can handle the extra watts an amp will give them. If not, then I'd say a good $100 comp set will do you just fine, but if you're going to amplify them, start with the $180's and up.
Another thing to consider, is in our soft-tops, you're never going to reach optimum sound quality, so IF you're considering purchasing a $500 kit or more, think twice, cause if you put them in say a Solstice Coupe, they'd blow you away at how much better they sound with a hardtop on. With that said, just buy the $1000 DLS or Hyrbid kit and chuck a hardtop on while you're at it!

My 2 cents!