is the fee of 19.95 really worth it i ask myself?
Oh absolutely... worth every penny and more. However, for an extra $30 - $40, you can get a more complete desktop experience with ObjectDesktop (Standard or Ultimate), which includes WindowBlinds and several other apps to completely customize the way your desktop looks and feels. Is it worth it? Yup, every penny and more, but like Philly said, only you can decide if you can afford it, whether you want to spend the money or not.
In the meantime, howver, enjoy your 30 day trial of WindowBlinds and do as Philly suggests, go to the galleries and take a look at what is possible with the software Stardock produces, it's pretty amazing stuff. 