On average, iPad cases run in the $30 to $60 range. The exceptions to that are higher-end ruggedized, custom handmade, and insanely expensive designer cases. Keeping those products and price ranges in mind, I'd say that a somewhat reasonable price point for the Grip would be around $100.
After all, it is a decent product. Aside from its seriously solid design—I'm pretty sure it would win a battle against my wall without a scratch—it provides a few new holding positions for the iPad. I instantly fell in love with the sudden freedom to securely hold my iPad in one hand—like a palette—without worrying that it'll slip out of my fingers or needing something to rest my tired hand against.
Now, while the Grip provides a more comfortable one-handed iPad experience, it actually makes hands-free usage hell. The thickness of the frame keeps my iPad from fitting onto my Apple dock, the additional weight makes other docks topple over, and the sheer bulk prevents me from slipping on a case with a kickstand. Sure, I could remove the Grip when I want to use a case or a dock, but that'd be a bit ridiculous—and I don't exactly carry an allen wrench everywhere I go. (It's worth noting that an allen wrench is included in the purchase price.)
As much as I adore the Grip and how it helps me hold my iPad, I'm truly struggling to recommend it to anyone except to folks who use $100 bills to light their imported cigars while paying someone to hold their iPads for them instead of using a dock. Some people might disagree, of course, and I won't hold it against them.
Just like I don't hold anything against my ColorWare contact over the fact that his voice had a tinge of awe when he shared that despite the Grip's order page just barely having gone live, someone had already ordered one. He sounded more surprised than I felt.