Do the designers think they are hitting a target market?
The designers don't factor into this. The show's producers are offering the prizes. They aren't "marketing" prizes to a target market; they're offering a chance to win these prizes to lucky contestants.
Is this what people really want more than an appliance or a trip?
In many cases, yes. A choice between a trip and designer fashion accessories might be a coin toss, depending on the player, but I feel safe in saying that the vast majority of women would definitely rather win those fashion items over appliances.
Part of the magic of being on a game show is not just the possibility of winning a prize. It's the possibility of winning a prize that you otherwise would not ordinarily be able to own.
As a guy, I can't relate to winning purses or handbags.
However, if I were to find my way on to the show, I can PROMISE that I would go crazy over the $9,000 BBQ island that has been offered in the past. I can't afford it, but if I were to WIN one, it would take a team of plastic surgeons a month to remove the smile from my face.
I know some women who feel the same way about designer handbags.